edited by Vernon Bogdanor
Blackwell Reference, 1991
Buku Referensi
edited by Heinz Eulau
Atherton Press, 1969
Buku Teks
Clinton, Richard L., author
Lexington Books, 1972
Buku Teks
by Carlton Clymer Rodee ... [et al.]
McGraw-Hill, 1983
Buku Teks
by Carlton Clymer Rodee ... [et al.]
McGraw-Hill Kogakusha, 1976
Buku Teks