Velasquez, Manuel G
Prentice-Hall, 2002
Buku Teks
by Joseph C. Latona ... [and others]
South-Western Publishing, 1984
Buku Teks
Tan, Joo Seng, author
McGraw-Hill , 2004
Buku Teks
by David F. Scott ... [and others]
Prentice-Hall, 1993
Buku Teks
Litvak, Isaiah A., author
McGraw-Hill Ryerson, 1984
Buku Teks