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
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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
Aspen Aerogels, Inc. Common 04523Y105 20,841 3,167,322 SH   SOLE n/a 3,167,322 0 0
BOK Financial Corp Common 05561Q201 163,501 2,896,899 SH   SOLE n/a 2,896,899 0 0
Boston Omaha Corp - CL A Common 101044105 3,055 190,927 SH   OTR n/a 140,932 0 49,995
Adobe Inc. Common 00724F101 526 1,208 SH   OTR n/a 0 0 1,208
Alphabet, Inc. - CL A Common 02079K305 404 285 SH   OTR n/a 0 0 285
Alphabet Inc. - CL C Common 02079K107 2,420 1,712 SH   OTR n/a 0 0 1,712
Analog Devices, Inc. Common 032654105 954 7,782 SH   OTR n/a 0 0 7,782
Berkshire Hathaway Inc. - CL B Common 084670702 2,939 16,464 SH   OTR n/a 0 0 16,464
Booking Holdings Inc. Common 09857L108 1,027 645 SH   OTR n/a 0 0 645
Comcast Corp - CL A Common 20030N101 1,399 35,890 SH   OTR n/a 0 0 35,890
CoStar Group, Inc. Common 22160N109 515 724 SH   OTR n/a 0 0 724
Facebook, Inc. - CL A Common 30303M102 1,792 7,893 SH   OTR n/a 0 0 7,893
Heico Corporation Common 422806109 1,214 12,186 SH   OTR n/a 0 0 12,186
JPMorgan Chase & Co. Common 46625H100 3,297 35,052 SH   OTR n/a 0 0 35,052
Liberty Broadband Corp - Series C Common 530307305 4,549 36,697 SH   OTR n/a 0 0 36,697
Microsoft Corp Common 594918104 4,597 22,589 SH   OTR n/a 0 0 22,589
Mohawk Industries, Inc. Common 608190104 2,155 21,177 SH   OTR n/a 0 0 21,177
Moodys Corp Common 615369105 2,174 7,913 SH   OTR n/a 0 0 7,913
MSCI Inc. Common 55354G100 515 1,542 SH   OTR n/a 0 0 1,542
PayPal Holdings, Inc. Common 70450Y103 537 3,083 SH   OTR n/a 0 0 3,083
Richardson Electronics, Ltd. Common 763165107 560 138,548 SH   OTR n/a 0 0 138,548
Ryanair Holdings PLC Common 783513203 1,838 27,709 SH   OTR n/a 0 0 27,709
S&P Global Inc. Common 78409V104 2,520 7,647 SH   OTR n/a 0 0 7,647
SAP SE Common 803054204 1,643 11,734 SH   OTR n/a 0 0 11,734
Telefonaktiebolaget LM Ericsson - Series B Common 294821608 1,753 188,451 SH   OTR n/a 0 0 188,451
Visa Inc. - CL A Common 92826C839 2,268 11,739 SH   OTR n/a 0 0 11,739