by Arthur J. Keown, John D. Martin, J. William Petty, and David F. Scott
Prentice-Hall, 2005
Buku Teks
Asch, David, author
Crest Publishing House, 1999
Buku Referensi
Shapiro, Alan C., author
Allyn and Bacon, 1991
Buku Teks
Shapiro, Alan C., author
Allyn and Bacon, 1986
Buku Teks
Abdullah, Fuad A., author
Prentice-Hall International, 1987
Buku Teks