Identify whether the following sources are primary authority or secondary authority:

a) Citizens Energy Coalition v. Sendak, 594 F.2d 1158 (7th Cir. 1979)

b) A book entitled Environmental Law

c) The discussion in Am. Jur. 2d about pollution control

d) 42 U.S.C. 6807a, relating to energy efficiency grants

e) The treaty signed by the United States and other parties entitled International Convention for the Regulation of Whaling

f) Janice Chon, Clean Power Plan, 7 Envtl. & Earth L.J. 105 (2017)