Syjuco, Jose G., author
Ne Day, 1977
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill , 1989
Buku Teks
edited by Steven W. Lee
Sage Publications, 2005
Buku Referensi
William G. ASP....[et.al] author
The Shoe String Press , 1985
Buku Teks
Eson, Morris E.
Holt, Rinehart and Winston, 1964
Buku Teks