Heffernan, James A. W., author
W.W. Norton & Company, 1990
Buku Referensi
Marius, Richard, author
McGraw-Hill, 1988
Buku Referensi
Kramer, Melinda G., author
Prentice-Hall, 1995
Buku Referensi
Guth, Hans P., author
Wadsworth, 1969
Buku Teks
Raimes, Ann, author
Wadsworth and Cengage Learning, 2013
Buku Teks