(a)Cross references. For provisions relating to tax-free sales of articles referred to in section 4071, see:(1) Section 4221, relating to certain tax-free sales, and the regulations thereunder in subpart H;(2) Section 4222, relating to registration, and the regulations thereunder in subpart H;(3) Section 4223, relating to special rules pertaining to further manufacture, and the regulations thereunder in subpart H; and(4) 28 FR 348, January 12, 1963, relating to the authorization of an exemption from the tax imposed by section 4071 by the Secretary of the Treasury under section 4293 for sales of certain tires and inner tubes sold to the American Red Cross on or after March 1, 1963.T.D. 7809, 47 FR 6008, Feb. 10, 1982 Secs. 4071(b), 4071(c), 4073(c), and 7805, Internal Revenue Code of 1954; 80 Stat. 331, 26 U.S.C. 4071(b) ; 68A Stat. 482, 26 U.S.C. 4071(c) ; 70 Stat. 389, 26 U.S.C. 4073(c) ; 68A Stat. 917, 26 U.S.C. 7805