Magee, John H.
R. D. Irwin, 1964
Buku Teks
Freddy Kusnady, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1973
UI - Skripsi (Membership)
Bruce D. Mudget [and others]
Alexander Hamilton Institute, 1962
Buku Teks
Mowbray, Albert H.
McGraw-Hill, 1955
Buku Teks
Goshay, Robert C.
R.D. Irwin , 1964
Buku Teks