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 83,765 1,806,452 SH   SOLE   1,806,452 0 0
3M CO COM 88579Y101 604 4,265 SH   SOLE   4,265 0 0
ABBOTT LABORATORIES COM 002824100 474 11,400 SH   SOLE   11,400 0 0
ABBVIE INC COM 00287Y109 463 8,016 SH   SOLE   8,016 0 0
ALTERA CORP COM 021441100 251 7,018 SH   SOLE   7,018 0 0
AMAZON.COM INC COM 023135106 205 637 SH   SOLE   637 0 0
AMBER ROAD INC COM 02318y108 938 54,088 SH   SOLE   54,088 0 0
AMERICAN TOWER CORP COM 03027X100 84,947 907,262 SH   SOLE   907,262 0 0
ANADARKO PETROLEUM CORP COM 032511107 538 5,300 SH   SOLE   5,300 0 0
ANSYS INC COM 03662Q105 167,280 2,210,647 SH   SOLE   2,210,647 0 0
APPLE COMPUTER INC COM 037833100 1,158 11,493 SH   SOLE   11,493 0 0
APPLIED MINERALS COM 03823m100 57 80,000 SH   SOLE   80,000 0 0
ATRION CORP COM 049904105 2,137 7,006 SH   SOLE   7,006 0 0
AUTOMATIC DATA PROCESSING COM 053015103 2,547 30,658 SH   SOLE   30,658 0 0
BECTON DICKINSON & CO COM 075887109 250 2,200 SH   SOLE   2,200 0 0
BERKSHIRE HATHAWAY INC COM 084670108 1,448 7 SH   SOLE   7 0 0
BERKSHIRE HATHAWAY INC. DEL CL COM 084670702 3,275 23,710 SH   SOLE   23,710 0 0
BIO-TECHNE CORP COM 09073M104 33,446 357,516 SH   SOLE   357,516 0 0
CANADIAN NATIONAL RAILROAD CO COM 136375102 1,419 20,000 SH   SOLE   20,000 0 0
CAPITAL ONE FINANCIAL COM 14040H105 2,199 26,938 SH   SOLE   26,938 0 0
CAREFUSION CORPORATION COM 14170T101 33,146 732,502 SH   SOLE   732,502 0 0
CARMAX INC COM 143130102 77,612 1,670,873 SH   SOLE   1,670,873 0 0
CELGENE CORP COM 151020104 121,551 1,282,456 SH   SOLE   1,282,456 0 0
CHEVRON CORP COM 166764100 1,292 10,827 SH   SOLE   10,827 0 0
CISCO SYSTEMS INC COM 17275R102 2,064 81,991 SH   SOLE   81,991 0 0
COCA COLA CO COM 191216100 1,159 27,162 SH   SOLE   27,162 0 0
COLGATE-PALMOLIVE COM 194162103 652 10,000 SH   SOLE   10,000 0 0
COMCAST CORP - A COM 20030N101 679 12,625 SH   SOLE   12,625 0 0
COMCAST CORP - A - SPL COM 20030N200 4,117 76,947 SH   SOLE   76,947 0 0
CONCHO RESOURCES INC COM 20605P101 79,592 634,757 SH   SOLE   634,757 0 0
CONCUR TECHNOLOGIES, INC. COM 206708109 71,745 565,727 SH   SOLE   565,727 0 0
CORE LABORATORIES NV COM N22717107 87,706 599,286 SH   SOLE   599,286 0 0
COSTAR GROUP INC. COM 22160n109 89,824 577,498 SH   SOLE   577,498 0 0
CROWN CASTLE INTL CORP COM 228227104 4,485 55,699 SH   SOLE   55,699 0 0
DEALERTRACK TECHNOLOGIES INC COM 242309102 75,585 1,741,190 SH   SOLE   1,741,190 0 0
DEERE & CO COM 244199105 219 2,673 SH   SOLE   2,673 0 0
DENTSPLY INTL COM 249030107 236 5,167 SH   SOLE   5,167 0 0
DISCOVER FINANCIAL SERVICES COM 254709108 117,511 1,824,981 SH   SOLE   1,824,981 0 0
DONALDSON INC COM 257651109 3,687 90,738 SH   SOLE   90,738 0 0
DORMAN PRODUCTS INC COM 258278100 7,679 191,693 SH   SOLE   191,693 0 0
DOUGLAS DYNAMICS INC COM 25960R105 737 37,781 SH   SOLE   37,781 0 0
DUKE REALTY CORP COM 264411505 267 15,550 SH   SOLE   15,550 0 0
EAST WEST BANCORP INC COM 27579R104 405 11,900 SH   SOLE   11,900 0 0
ECOLAB INC COM 278865100 118,390 1,031,000 SH   SOLE   1,031,000 0 0
EINSTEIN NOAH RESTAURANT GP IN COM 28257u104 729 36,150 SH   SOLE   36,150 0 0
ELI LILLY & CO COM 532457108 620 9,554 SH   SOLE   9,554 0 0
ELLIE MAE INC COM 28849P100 1,883 57,754 SH   SOLE   57,754 0 0
EMERSON COM 291011104 482 7,701 SH   SOLE   7,701 0 0
ENTERPRISE PRODUCTS PARTNERS L COM 293792107 613 15,200 SH   SOLE   15,200 0 0
ENVESTNET INC COM 29404K106 989 21,967 SH   SOLE   21,967 0 0
EQT CORPORATION COM 26884L109 4,648 50,773 SH   SOLE   50,773 0 0
EQUITY RESIDENTIAL PROPERTYS I COM 29476l107 479 7,776 SH   SOLE   7,776 0 0
EXAMWORKS GROUP INC. COM 30066a105 63,209 1,930,041 SH   SOLE   1,930,041 0 0
EXPEDITORS INTERNATIONAL COM 302130109 40,099 988,142 SH   SOLE   988,142 0 0
EXPONENT INC. COM 30214U102 36,567 515,903 SH   SOLE   515,903 0 0
EXPRESS SCRIPTS INC COM 30219G108 1,376 19,487 SH   SOLE   19,487 0 0
EXXON MOBIL CORP COM 30231G102 1,802 19,160 SH   SOLE   19,160 0 0
FASTENAL CO COM 311900104 231,952 5,165,960 SH   SOLE   5,165,960 0 0
FINANCIAL ENGINES INC COM 317485100 33,790 987,581 SH   SOLE   987,581 0 0
FISERV INC COM 337738108 4,414 68,298 SH   SOLE   68,298 0 0
FORTINET INC COM 34959e109 1,121 44,360 SH   SOLE   44,360 0 0
FREEPORT MCMORAN COPPER & GOLD COM 35671D857 425 13,014 SH   SOLE   13,014 0 0
GENERAL ELECTRIC COM 369604103 3,235 126,281 SH   SOLE   126,281 0 0
GENUINE PARTS COMPANY COM 372460105 263 2,999 SH   SOLE   2,999 0 0
GILEAD SCIENCES INC. COM 375558103 760 7,142 SH   SOLE   7,142 0 0
GOOGLE INC CL C COM 38259P706 260 450 SH   SOLE   450 0 0
GOOGLE INC CLASS A COM 38259P508 265 450 SH   SOLE   450 0 0
GUIDEWIRE SOFTWARE INC COM 40171V100 307 6,924 SH   SOLE   6,924 0 0
HCP INC COM 40414L109 4,152 104,555 SH   SOLE   104,555 0 0
HEALTHCARE SERVICES GROUP INC COM 421906108 61,383 2,145,517 SH   SOLE   2,145,517 0 0
HESS CORPORATION COM 42809h107 477 5,052 SH   SOLE   5,052 0 0
HIBBETT SPORTS INC COM 428567101 363 8,505 SH   SOLE   8,505 0 0
HOME DEPOT COM 437076102 275 2,999 SH   SOLE   2,999 0 0
ILLINOIS TOOL WORKS COM 452308109 203 2,400 SH   SOLE   2,400 0 0
ILLUMINA INC COM 452327109 27,827 169,762 SH   SOLE   169,762 0 0
IMAX CORP COM 45245E109 73,334 2,670,583 SH   SOLE   2,670,583 0 0
INTEL CORP COM 458140100 15,584 447,556 SH   SOLE   447,556 0 0
INTL BUSINESS MACH CORP COM 459200101 2,236 11,777 SH   SOLE   11,777 0 0
INTUITIVE SURGICAL INC COM 46120e602 51,355 111,202 SH   SOLE   111,202 0 0
INVENTURE FOODS INC COM 461212102 246 18,989 SH   SOLE   18,989 0 0
J P MORGAN CHASE & CO COM 46625H100 311 5,169 SH   SOLE   5,169 0 0
JACOBS ENGINEERING CP INC COM 469814107 65,675 1,345,246 SH   SOLE   1,345,246 0 0
JOHNSON & JOHNSON COM 478160104 10,814 101,455 SH   SOLE   101,455 0 0
KINDER MORGAN ENERGY COM 494550106 215 2,300 SH   SOLE   2,300 0 0
LABORATORY CORP OF AMERICA HOL COM 50540R409 2,438 23,965 SH   SOLE   23,965 0 0
LINCOLN NATL CORP COM 534187109 297 5,536 SH   SOLE   5,536 0 0
LKQ CORP COM 501889208 140,894 5,298,749 SH   SOLE   5,298,749 0 0
LYNAS CORP LTD COM Q5683J103 5 75,000 SH   SOLE   75,000 0 0
M&T BANK CORP COM 55261F104 387 3,138 SH   SOLE   3,138 0 0
MACY'S, INC. COM 55616P104 341 5,863 SH   SOLE   5,863 0 0
MAGELLAN MIDSTREAM PARTNERS LP COM 559080106 303 3,600 SH   SOLE   3,600 0 0
MARKEL CORP COM 570535104 131,768 207,133 SH   SOLE   207,133 0 0
MASTERCARD INC CL A COM 57636Q104 1,859 25,150 SH   SOLE   25,150 0 0
McCORMICK & CO COM 579780206 957 14,310 SH   SOLE   14,310 0 0
MERCK & CO COM 58933Y105 1,162 19,600 SH   SOLE   19,600 0 0
MERIDIAN BIOSCIENCE INC. COM 589584101 226 12,800 SH   SOLE   12,800 0 0
MICROSOFT CORP COM 594918104 2,745 59,201 SH   SOLE   59,201 0 0
MIDDLEBY CORP COM 596278101 1,286 14,596 SH   SOLE   14,596 0 0
MONRO MUFFLER BRAKE COM 610236101 446 9,192 SH   SOLE   9,192 0 0
MOODYS CORP COM 615369105 124,910 1,321,794 SH   SOLE   1,321,794 0 0
NATIONAL AMERICAN UNIV HOLDING COM 63245Q105 46 15,000 SH   SOLE   15,000 0 0
NATIONAL INFORMATION CONSORTIU COM 62914b100 536 31,150 SH   SOLE   31,150 0 0
NEOGEN CORP COM 640491106 387 9,800 SH   SOLE   9,800 0 0
O REILLY AUTOMOTIVE INC COM 67103H107 16,432 109,283 SH   SOLE   109,283 0 0
ONEBEACON INSURANCE GP COM G67742109 429 27,849 SH   SOLE   27,849 0 0
PANERA BREAD CO COM 69840W108 51,049 313,720 SH   SOLE   313,720 0 0
PAYCHEX COM 704326107 4,334 98,050 SH   SOLE   98,050 0 0
PEPSICO INC COM 713448108 388 4,173 SH   SOLE   4,173 0 0
PFIZER INC COM 717081103 1,175 39,749 SH   SOLE   39,749 0 0
PHILIP MORRIS INTL COM 718172109 482 5,776 SH   SOLE   5,776 0 0
PINNACLE WEST CAPITOL CORP COM 723484101 240 4,400 SH   SOLE   4,400 0 0
PNC FINANCIAL SVCS INC COM 693475105 2,250 26,290 SH   SOLE   26,290 0 0
POTASH CORP OF SASKATCHEWAN COM 73755L107 26,948 779,742 SH   SOLE   779,742 0 0
PRECISION CASTPARTS CORP COM 740189105 426 1,800 SH   SOLE   1,800 0 0
PRICE SMART INC COM 741511109 60,253 703,557 SH   SOLE   703,557 0 0
PROCTER & GAMBLE CO COM 742718109 21,855 260,989 SH   SOLE   260,989 0 0
QUALCOMM INC COM 747525103 96,317 1,288,175 SH   SOLE   1,288,175 0 0
RANGE RESOURCES CORP COM 75281A109 41,672 614,537 SH   SOLE   614,537 0 0
RED HAT INC. COM 756577102 120,213 2,140,928 SH   SOLE   2,140,928 0 0
RENAISSANCE RE HOLDINGS LTD COM G7496G103 600 6,000 SH   SOLE   6,000 0 0
ROPER INDUSTRIES, INC COM 776696106 98,526 673,499 SH   SOLE   673,499 0 0
SBA COMMUNICATIONS CORP COM 78388J106 1,597 14,397 SH   SOLE   14,397 0 0
SCHLUMBERGER LTD COM 806857108 63,335 622,827 SH   SOLE   622,827 0 0
SEI INVESTMENTS CO COM 784117103 132,486 3,663,873 SH   SOLE   3,663,873 0 0
SIGNET JEWELERS LTD COM g81276100 83,521 733,221 SH   SOLE   733,221 0 0
SILVER WHEATON CORP COM 828336107 299 15,000 SH   SOLE   15,000 0 0
SMITH & NEPHEW PLC COM 83175M205 253 3,000 SH   SOLE   3,000 0 0
SOTHERLY HOTELS, INC COM 83600C103 106 13,625 SH   SOLE   13,625 0 0
SOUTHWESTERN ENERGY CO COM 845467109 642 18,359 SH   SOLE   18,359 0 0
STERICYCLE INC COM 858912108 119,275 1,023,290 SH   SOLE   1,023,290 0 0
STRYKER CORP COM 863667101 274 3,397 SH   SOLE   3,397 0 0
T ROWE PRICE GROUP INC COM 74144T108 16,512 210,611 SH   SOLE   210,611 0 0
TANGOE INC COM 87582Y108 22,758 1,679,570 SH   SOLE   1,679,570 0 0
TESLA MOTORS INC COM 88160R101 212 875 SH   SOLE   875 0 0
TRIMBLE NAVIGATION LTD COM 896239100 117,679 3,858,335 SH   SOLE   3,858,335 0 0
TYLER TECHNOLOGIES INC COM 902252105 43,865 496,208 SH   SOLE   496,208 0 0
U.S. BANCORP COM 902973304 1,192 28,486 SH   SOLE   28,486 0 0
ULTIMATE SOFTWARE INC COM 90385d107 233 1,643 SH   SOLE   1,643 0 0
UNDER ARMOUR, INC COM 904311107 546 7,900 SH   SOLE   7,900 0 0
UNION PACIFIC CORP COM 907818108 222 2,050 SH   SOLE   2,050 0 0
UNITED TECHNOLOGIES CORP COM 913017109 430 4,071 SH   SOLE   4,071 0 0
VENTAS INC COM 92276f100 2,372 38,288 SH   SOLE   38,288 0 0
VERISK ANALYTICS COM 92345Y106 99,596 1,635,664 SH   SOLE   1,635,664 0 0
VERIZON COMMUNICATIONS COM 92343V104 241 4,813 SH   SOLE   4,813 0 0
VF CORP COM 918204108 264 4,000 SH   SOLE   4,000 0 0
VISA INC COM 92826C839 115,649 542,011 SH   SOLE   542,011 0 0
WAGEWORKS INC COM 930427109 101,913 2,238,376 SH   SOLE   2,238,376 0 0
WALT DISNEY CO COM 254687106 794 8,919 SH   SOLE   8,919 0 0
WASTE CONNECTIONS INC COM 941053100 90,115 1,857,275 SH   SOLE   1,857,275 0 0
WATSCO INC CL A COM 942622200 465 5,400 SH   SOLE   5,400 0 0
WELLS FARGO & CO COM 949746101 366 7,055 SH   SOLE   7,055 0 0
WHOLE FOODS MARKET COM 966837106 602 15,800 SH   SOLE   15,800 0 0
WR BERKLEY CORP COM 084423102 2,916 60,995 SH   SOLE   60,995 0 0
WSFS FINANCIAL CORPORATION COM 929328102 203 2,841 SH   SOLE   2,841 0 0
XOOM CORPORATION COM 98419Q101 1,391 63,379 SH   SOLE   63,379 0 0
ZOE'S KITCHEN INC COM 98979J109 347 11,269 SH   SOLE   11,269 0 0
ISHARES TR MSCI EAFE INDEX FD ETFS 464287465 267 4,169 SH   SOLE   4,169 0 0
VANGUARD DIVIDEND ETFS 921908844 902 11,725 SH   SOLE   11,725 0 0
VANGUARD FTSE ALL-WORLD EX-US ETFS 922042775 2,775 56,347 SH   SOLE   56,347 0 0
VANGUARD FTSE EMERGING MARKETS ETFS 922042858 539 12,925 SH   SOLE   12,925 0 0
VANGUARD HIGH DIVIDEND YIELD E ETFS 921946406 329 4,950 SH   SOLE   4,950 0 0
VANGUARD INDEX REIT ETF ETFS 922908553 406 5,655 SH   SOLE   5,655 0 0