Ozcan, Yasar A.
Jossey- Bass, 2009
Buku Teks
Spiegel, Allen D.
Ablex Publishing Corporation, 1991
Buku Referensi
Shi, Leiyu
Delmar Cengage Learning, 2008
Buku Teks
edited by Paul M. Wortman
Sage, 1981
Buku Teks
Stryker, Perrin
McGraw-Hill, 1954
Buku Teks