Checkbook IRA & 401(k) Tax and Labor Code

26 U.S. Code § 401 – Qualified pension, profit-sharing, and stock bonus plans

26 U.S. Code § 408 – Individual retirement accounts

26 U.S. Code § 511 – Imposition of tax on unrelated business income of charitable, etc., organizations

26 U.S. Code § 512 – Unrelated business taxable income

26 U.S. Code § 513 – Unrelated trade or business

26 U.S. Code § 514 – Unrelated debt-financed income

26 U.S. Code § 4975 – Tax on prohibited transactions

USCODE-2015-title29-Chapter 8 – ERISA

Checkbook IRA & 401(k) Tax and Labor Regulations

29 CFR 2510.3-3 – Employee benefit plan.