For each of the following citations, identify the type of authority (statutory, administrative, or judicial) and explain the citation.
a. Reg. Sec. 1.111-1(b)
b. IRC Sec. 469(c)(7)(B)(i)
c. Rev. Rul. 82-204, 1982-2 C.B. 192
d. Amdahl Corp., 108 TC 507 (1997)
e. PLR 9727004
f. Hills v. Comm., 50 AFTR2d 82-6070 (11th Cir., 1982)