Dunn, S. Watson
Buku Teks
Schwartz, Harry, author
Atheneum, 1965
Buku Teks
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1991
UI - Skripsi (Membership)
Kirkpatrick, C.A., author
Houghton Miffiln, 1959
Buku Teks
Smith, George Horsley, author
McGraw-Hill, 1954
Buku Teks