Herring, E. Pendleton, author
McGraw-Hill, 1936
Buku Teks
Peters, B. Guy, author
Routledge, 2009
Buku Teks
Denhardt, Robert B., author
Thomson, 2009
Buku Teks
Nigro, Felix A., author
Harper and Row , 1977
Buku Teks
Henry, Nicholas
Prentice-Hall, 1992
Buku Teks