Jones, Thomas H.
Reston Publishing Company, 1978
Buku Referensi
Charles A Happer
USA : McGraw-Hill, Inc., 1970
Buku Teks
editor, Milton Kaufman, Arthur H. Seidman
McGraw-Hill, 1984
Buku Referensi
Donald G. Fink, editor-in-chief, Alexander A. McKenzie, assistant editor
McGraw-Hill, 1975
Buku Referensi
edited by Robert W. Landee, Donovan C. Davis, Albert P. Albrecht
McGraw-Hill, 1977
Buku Referensi