26 U.S.C. § 6680
Section, added Pub. L. 88-563, §6(a), Sept. 2, 1964, 78 Stat. 845; amended Pub. L. 91-128, §4(h)(1), Nov. 26, 1969, 83 Stat. 268; Pub. L. 92-9, §3(j)(2), Apr. 1, 1971, 85 Stat. 22, related to failure to file interest equalization tax returns.