Rudelius, William, author
Harcourt Brace Jovanovich , 1973
Buku Teks
Schall, Lawrence D., author
McGraw-Hill 1982, 1982
Buku Teks
Bardo, John W.
F.E. Peacock Publishers, 1982
Buku Teks
Hill, John William, 1933-, author
Upper Saddle RIver Prentice Hall 1997,
Buku Teks
Roberts, E.A
Chapman & Hall, 1992
Buku Teks