Universitas Indonesia, 1989
Buku Referensi
Havelock, Ronald G.
University of Michigan, 1973
Buku Teks
U.S. Small Business Administration , 1977
Buku Teks
Kilgannon, Pete, author
McGraw-Hill, 1980
Buku Teks
Bryson, John A., author
American Institute of Banking, 1959
Buku Teks