Section, act July 1, 1944, ch. 373, title III, § 312, formerly § 306, as added Aug. 2, 1956, ch. 871, title I, § 101, 70 Stat. 923; amended July 23, 1959, Pub. L. 86–105, § 1, 73 Stat. 239; Sept 8, 1960, Pub. L. 86–720, § 1(b), 74 Stat. 820; Aug. 27, 1964, Pub. L. 88–497, § 2, 78 Stat. 613; Aug. 16, 1968, Pub. L. 90–490, title III, § 302(b), 82 Stat. 789; Mar. 12, 1970, Pub. L. 91–208, § 3, 84 Stat. 52; Oct. 30, 1970, Pub. L. 91–515, title VI, § 601(b)(2), 84 Stat. 1311; June 18, 1973, Pub. L. 93–45, title I, § 104(a), 87 Stat. 91; renumbered § 312 and amended July 23, 1974, Pub. L. 93–353, title I, § 102(b), 88 Stat. 362; Oct. 12, 1976, Pub. L. 94–484, title I, § 101(a)(1), 90 Stat. 2244, related to graduate or specialized training for physicians, engineers, nurses, and other professional personnel.