The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3D SYSTEMS CORP COM 88554D205 81,424 1,376,571 SH   SOLE   1,376,571 0 0
3M CO COM 88579Y101 579 4,265 SH   SOLE   4,265 0 0
ABBOTT LABORATORIES COM 002824100 484 12,566 SH   SOLE   12,566 0 0
ABBVIE INC COM 00287Y109 543 10,566 SH   SOLE   10,566 0 0
ACTUANT CORP A COM 00508X203 2,143 62,758 SH   SOLE   62,758 0 0
ALTERA CORP COM 021441100 344 9,482 SH   SOLE   9,482 0 0
AMBER ROAD INC COM 02318y108 1,168 75,845 SH   SOLE   75,845 0 0
AMERICAN TOWER CORP COM 03027X100 78,433 958,018 SH   SOLE   958,018 0 0
ANADARKO PETROLEUM CORP COM 032511107 619 7,300 SH   SOLE   7,300 0 0
ANSYS INC COM 03662Q105 167,937 2,180,440 SH   SOLE   2,180,440 0 0
APACHE CORP COM 037411105 211 2,541 SH   SOLE   2,541 0 0
APPLE COMPUTER INC COM 037833100 907 1,689 SH   SOLE   1,689 0 0
APPLIED MINERALS COM 03823m100 94 130,000 SH   SOLE   130,000 0 0
ATRION CORP COM 049904105 1,704 5,567 SH   SOLE   5,567 0 0
AUTOMATIC DATA PROCESSING COM 053015103 2,486 32,175 SH   SOLE   32,175 0 0
BECTON DICKINSON & CO COM 075887109 263 2,248 SH   SOLE   2,248 0 0
BERKSHIRE HATHAWAY INC COM 084670108 1,311 7 SH   SOLE   7 0 0
BERKSHIRE HATHAWAY INC. DEL CL COM 084670702 3,032 24,260 SH   SOLE   24,260 0 0
CANADIAN NATIONAL RAILROAD CO COM 136375102 562 10,000 SH   SOLE   10,000 0 0
CAPITAL ONE FINANCIAL COM 14040H105 2,079 26,938 SH   SOLE   26,938 0 0
CAREFUSION CORPORATION COM 14170T101 44,808 1,114,080 SH   SOLE   1,114,080 0 0
CARMAX INC COM 143130102 35,467 757,852 SH   SOLE   757,852 0 0
CARTERS, INC. COM 146229109 25,405 327,172 SH   SOLE   327,172 0 0
CELGENE CORP COM 151020104 86,636 620,605 SH   SOLE   620,605 0 0
CHEVRON CORP COM 166764100 1,413 11,881 SH   SOLE   11,881 0 0
CISCO SYSTEMS INC COM 17275R102 2,121 94,642 SH   SOLE   94,642 0 0
CLEAN HARBORS INC COM 184496107 69,170 1,262,457 SH   SOLE   1,262,457 0 0
COCA COLA CO COM 191216100 1,050 27,162 SH   SOLE   27,162 0 0
COGNIZANT TECH SOLUTIONS CORP COM 192446102 202 4,000 SH   SOLE   4,000 0 0
COLGATE-PALMOLIVE COM 194162103 649 10,000 SH   SOLE   10,000 0 0
COMCAST CORP - A COM 20030N101 657 13,125 SH   SOLE   13,125 0 0
COMCAST CORP - A - SPL COM 20030N200 3,884 79,647 SH   SOLE   79,647 0 0
CONCHO RESOURCES INC COM 20605P101 115,217 940,544 SH   SOLE   940,544 0 0
CONCUR TECHNOLOGIES, INC. COM 206708109 89,892 907,362 SH   SOLE   907,362 0 0
CORE LABORATORIES NV COM N22717107 70,736 356,460 SH   SOLE   356,460 0 0
COSTAR GROUP INC. COM 22160n109 93,360 499,945 SH   SOLE   499,945 0 0
CROWN CASTLE INTL CORP COM 228227104 4,508 61,099 SH   SOLE   61,099 0 0
DEALERTRACK TECHNOLOGIES INC COM 242309102 71,871 1,461,095 SH   SOLE   1,461,095 0 0
DENTSPLY INTL COM 249030107 1,526 33,140 SH   SOLE   33,140 0 0
DISCOVER FINANCIAL SERVICES COM 254709108 93,901 1,613,700 SH   SOLE   1,613,700 0 0
DONALDSON INC COM 257651109 4,613 108,807 SH   SOLE   108,807 0 0
DORMAN PRODUCTS INC COM 258278100 9,477 160,464 SH   SOLE   160,464 0 0
DOUGLAS DYNAMICS INC COM 25960R105 785 45,036 SH   SOLE   45,036 0 0
DUKE REALTY CORP COM 264411505 262 15,550 SH   SOLE   15,550 0 0
EAST WEST BANCORP INC COM 27579R104 558 15,300 SH   SOLE   15,300 0 0
ECOLAB INC COM 278865100 119,022 1,102,159 SH   SOLE   1,102,159 0 0
EINSTEIN NOAH RESTAURANT GP IN COM 28257u104 622 37,796 SH   SOLE   37,796 0 0
ELI LILLY & CO COM 532457108 583 9,899 SH   SOLE   9,899 0 0
ELLIE MAE INC COM 28849P100 1,827 63,351 SH   SOLE   63,351 0 0
EMERSON COM 291011104 428 6,401 SH   SOLE   6,401 0 0
ENTERPRISE PRODUCTS PARTNERS L COM 293792107 614 8,850 SH   SOLE   8,850 0 0
ENVESTNET INC COM 29404K106 820 20,409 SH   SOLE   20,409 0 0
EQT CORPORATION COM 26884L109 5,452 56,226 SH   SOLE   56,226 0 0
EQUITY RESIDENTIAL PROPERTYS I COM 29476l107 362 6,248 SH   SOLE   6,248 0 0
EXAMWORKS GROUP INC. COM 30066a105 66,397 1,896,516 SH   SOLE   1,896,516 0 0
EXPEDITORS INTERNATIONAL COM 302130109 84,371 2,128,973 SH   SOLE   2,128,973 0 0
EXPONENT INC. COM 30214U102 41,804 556,937 SH   SOLE   556,937 0 0
EXPRESS SCRIPTS INC COM 30219G108 1,327 17,666 SH   SOLE   17,666 0 0
EXXON MOBIL CORP COM 30231G102 2,087 21,367 SH   SOLE   21,367 0 0
FASTENAL CO COM 311900104 270,537 5,487,575 SH   SOLE   5,487,575 0 0
FINANCIAL ENGINES INC COM 317485100 41,297 813,253 SH   SOLE   813,253 0 0
FISERV INC COM 337738108 3,947 69,632 SH   SOLE   69,632 0 0
FORTINET INC COM 34959e109 1,408 63,909 SH   SOLE   63,909 0 0
FREEPORT MCMORAN COPPER & GOLD COM 35671D857 391 11,814 SH   SOLE   11,814 0 0
GENERAL ELECTRIC COM 369604103 3,449 133,231 SH   SOLE   133,231 0 0
GENUINE PARTS COMPANY COM 372460105 304 3,499 SH   SOLE   3,499 0 0
GILEAD SCIENCES INC. COM 375558103 493 6,960 SH   SOLE   6,960 0 0
GOOGLE INC CL C COM 38259P706 502 450 SH   SOLE   450 0 0
HCP INC COM 40414L109 4,305 110,972 SH   SOLE   110,972 0 0
HEALTHCARE SERVICES GROUP INC COM 421906108 66,830 2,299,736 SH   SOLE   2,299,736 0 0
HESS CORPORATION COM 42809h107 290 3,502 SH   SOLE   3,502 0 0
HIBBETT SPORTS INC COM 428567101 658 12,440 SH   SOLE   12,440 0 0
HOME DEPOT COM 437076102 237 2,999 SH   SOLE   2,999 0 0
IDEXX LABORATORIES, INC. COM 45168D104 522 4,300 SH   SOLE   4,300 0 0
ILLINOIS TOOL WORKS COM 452308109 211 2,598 SH   SOLE   2,598 0 0
ILLUMINA INC COM 452327109 29,671 199,590 SH   SOLE   199,590 0 0
INTEL CORP COM 458140100 13,230 512,502 SH   SOLE   512,502 0 0
INTL BUSINESS MACH CORP COM 459200101 2,792 14,507 SH   SOLE   14,507 0 0
INTUITIVE SURGICAL INC COM 46120e602 51,578 117,760 SH   SOLE   117,760 0 0
INVENTURE FOODS INC COM 461212102 255 18,253 SH   SOLE   18,253 0 0
J P MORGAN CHASE & CO COM 46625H100 361 5,939 SH   SOLE   5,939 0 0
JACOBS ENGINEERING CP INC COM 469814107 93,314 1,469,504 SH   SOLE   1,469,504 0 0
JOHNSON & JOHNSON COM 478160104 10,128 103,107 SH   SOLE   103,107 0 0
JOHNSON CONTROLS INC COM 478366107 237 5,016 SH   SOLE   5,016 0 0
LABORATORY CORP OF AMERICA HOL COM 50540R409 5,294 53,902 SH   SOLE   53,902 0 0
LAKE SHORE GOLD CORP COM 510728108 16 25,000 SH   SOLE   25,000 0 0
LANDAUER, INC. COM 51476k103 271 5,987 SH   SOLE   5,987 0 0
LINCOLN NATL CORP COM 534187109 341 6,736 SH   SOLE   6,736 0 0
LIQUIDITY SERVICES INC COM 53635B107 18,991 729,028 SH   SOLE   729,028 0 0
LKQ CORP COM 501889208 127,013 4,820,223 SH   SOLE   4,820,223 0 0
LYNAS CORP LTD COM Q5683J103 14 75,000 SH   SOLE   75,000 0 0
M&T BANK CORP COM 55261F104 381 3,138 SH   SOLE   3,138 0 0
MACY'S, INC. COM 55616P104 348 5,863 SH   SOLE   5,863 0 0
MAG SILVER CORP COM 55903Q104 517 75,000 SH   SOLE   75,000 0 0
MAGELLAN MIDSTREAM PARTNERS LP COM 559080106 279 4,000 SH   SOLE   4,000 0 0
MARKEL CORP COM 570535104 139,843 234,596 SH   SOLE   234,596 0 0
MASTERCARD INC CL A COM 57636Q104 1,879 25,150 SH   SOLE   25,150 0 0
McCORMICK & CO COM 579780206 1,012 14,110 SH   SOLE   14,110 0 0
MERCK & CO COM 58933Y105 1,363 24,003 SH   SOLE   24,003 0 0
MERIDIAN BIOSCIENCE INC. COM 589584101 279 12,800 SH   SOLE   12,800 0 0
MICROSOFT CORP COM 594918104 2,451 59,799 SH   SOLE   59,799 0 0
MIDDLEBY CORP COM 596278101 2,421 9,164 SH   SOLE   9,164 0 0
MONRO MUFFLER BRAKE COM 610236101 686 12,052 SH   SOLE   12,052 0 0
MOODYS CORP COM 615369105 110,831 1,397,269 SH   SOLE   1,397,269 0 0
NATIONAL INFORMATION CONSORTIU COM 62914b100 1,490 77,172 SH   SOLE   77,172 0 0
NEOGEN CORP COM 640491106 441 9,800 SH   SOLE   9,800 0 0
NESTLE S.A. COM 641069406 254 3,375 SH   SOLE   3,375 0 0
O REILLY AUTOMOTIVE INC COM 67103H107 16,288 109,766 SH   SOLE   109,766 0 0
ONEBEACON INSURANCE GP COM G67742109 357 23,122 SH   SOLE   23,122 0 0
PANERA BREAD CO COM 69840W108 27,727 157,119 SH   SOLE   157,119 0 0
PAYCHEX COM 704326107 5,189 121,816 SH   SOLE   121,816 0 0
PEPSICO INC COM 713448108 369 4,422 SH   SOLE   4,422 0 0
PFIZER INC COM 717081103 1,272 39,610 SH   SOLE   39,610 0 0
PHILIP MORRIS INTL COM 718172109 375 4,575 SH   SOLE   4,575 0 0
PINNACLE WEST CAPITOL CORP COM 723484101 241 4,400 SH   SOLE   4,400 0 0
PNC FINANCIAL SVCS INC COM 693475105 2,305 26,493 SH   SOLE   26,493 0 0
POTASH CORP OF SASKATCHEWAN COM 73755L107 28,825 795,825 SH   SOLE   795,825 0 0
PRECISION CASTPARTS CORP COM 740189105 455 1,800 SH   SOLE   1,800 0 0
PRICE SMART INC COM 741511109 33,743 334,316 SH   SOLE   334,316 0 0
PROCTER & GAMBLE CO COM 742718109 23,768 294,887 SH   SOLE   294,887 0 0
QUALCOMM INC COM 747525103 144,716 1,835,099 SH   SOLE   1,835,099 0 0
QUANTA SERVICES INC COM 74762e102 3,350 90,791 SH   SOLE   90,791 0 0
RANGE RESOURCES CORP COM 75281A109 56,235 677,777 SH   SOLE   677,777 0 0
RAVEN INDUSTRIES, INC. COM 754212108 308 9,410 SH   SOLE   9,410 0 0
REALPAGE, INC. COM 75606n109 2,287 125,935 SH   SOLE   125,935 0 0
RED HAT INC. COM 756577102 113,188 2,136,436 SH   SOLE   2,136,436 0 0
RENAISSANCE RE HOLDINGS LTD COM G7496G103 678 6,950 SH   SOLE   6,950 0 0
ROPER INDUSTRIES, INC COM 776696106 96,531 723,028 SH   SOLE   723,028 0 0
SBA COMMUNICATIONS CORP COM 78388J106 1,870 20,560 SH   SOLE   20,560 0 0
SCHLUMBERGER LTD COM 806857108 130,143 1,334,803 SH   SOLE   1,334,803 0 0
SEI INVESTMENTS CO COM 784117103 122,434 3,642,796 SH   SOLE   3,642,796 0 0
SIGNET JEWELERS LTD COM g81276100 81,782 772,552 SH   SOLE   772,552 0 0
SILVER WHEATON CORP COM 828336107 340 15,000 SH   SOLE   15,000 0 0
SMITH & NEPHEW PLC COM 83175M205 229 3,000 SH   SOLE   3,000 0 0
SOTHERLY HOTELS, INC COM 55302L102 103 16,125 SH   SOLE   16,125 0 0
SOUTHWESTERN ENERGY CO COM 845467109 74,913 1,628,200 SH   SOLE   1,628,200 0 0
STERICYCLE INC COM 858912108 123,644 1,088,224 SH   SOLE   1,088,224 0 0
STONEMOR PARTNERS LP COM 86183Q100 302 12,000 SH   SOLE   12,000 0 0
STRYKER CORP COM 863667101 375 4,609 SH   SOLE   4,609 0 0
T ROWE PRICE GROUP INC COM 74144T108 23,128 280,851 SH   SOLE   280,851 0 0
TANGOE INC COM 87582Y108 15,473 832,354 SH   SOLE   832,354 0 0
TECHNE CORP COM 878377100 1,177 13,784 SH   SOLE   13,784 0 0
TELEFLEX INC COM 879369106 295 2,750 SH   SOLE   2,750 0 0
TRIMBLE NAVIGATION LTD COM 896239100 162,026 4,168,399 SH   SOLE   4,168,399 0 0
TYLER TECHNOLOGIES INC COM 902252105 44,518 531,999 SH   SOLE   531,999 0 0
U.S. BANCORP COM 902973304 1,231 28,725 SH   SOLE   28,725 0 0
UNDER ARMOUR, INC COM 904311107 459 4,000 SH   SOLE   4,000 0 0
UNION PACIFIC CORP COM 907818108 211 1,125 SH   SOLE   1,125 0 0
UNITED TECHNOLOGIES CORP COM 913017109 429 3,671 SH   SOLE   3,671 0 0
VENTAS INC COM 92276f100 2,503 41,325 SH   SOLE   41,325 0 0
VERISK ANALYTICS COM 92345Y106 83,599 1,394,238 SH   SOLE   1,394,238 0 0
VERIZON COMMUNICATIONS COM 92343V104 409 8,601 SH   SOLE   8,601 0 0
VF CORP COM 918204108 248 4,000 SH   SOLE   4,000 0 0
VISA INC COM 92826C839 115,877 536,814 SH   SOLE   536,814 0 0
VODAFONE GROUP PLC NEW COM 92857W209 261 7,085 SH   SOLE   7,085 0 0
WAGEWORKS INC COM 930427109 98,583 1,756,962 SH   SOLE   1,756,962 0 0
WALT DISNEY CO COM 254687106 714 8,919 SH   SOLE   8,919 0 0
WASTE CONNECTIONS INC COM 941053100 111,421 2,540,377 SH   SOLE   2,540,377 0 0
WELLS FARGO & CO COM 949746101 351 7,055 SH   SOLE   7,055 0 0
WHOLE FOODS MARKET COM 966837106 801 15,800 SH   SOLE   15,800 0 0
WR BERKLEY CORP COM 084423102 3,416 82,078 SH   SOLE   82,078 0 0
ISHARES TR MSCI EAFE INDEX FD ETFS 464287465 391 5,814 SH   SOLE   5,814 0 0
VANGUARD DIVIDEND ETFS 921908844 848 11,275 SH   SOLE   11,275 0 0
VANGUARD FTSE ALL-WORLD EX-US ETFS 922042775 2,730 54,272 SH   SOLE   54,272 0 0
VANGUARD FTSE EMERGING MARKETS ETFS 922042858 524 12,925 SH   SOLE   12,925 0 0
VANGUARD HIGH DIVIDEND YIELD E ETFS 921946406 301 4,775 SH   SOLE   4,775 0 0
VANGUARD INDEX REIT ETF ETFS 922908553 399 5,655 SH   SOLE   5,655 0 0