Kuzma, Jan W.
Mayfield Publ., 1984
Buku Teks
Schork, M. Anthony
Prentice-Hall, 2000
Buku Teks
Samuel, Myra L.
Pearson - Prentice Hall, 2003
Buku Teks
Kaplan, Robert M.
Allyn and Bacon , 1987
Buku Teks
Dunn, Olive Jean
John Wiley & Sons, 1977
Buku Teks