Gayle, Mike, author
Seeing other people, 2015
Buku Teks
Larson, Ron, 1941-, author
Brooks/Cole Cengage Learning, 2012
Buku Teks
Rintoul, M. C., author
Routledge, 1993
Buku Referensi
Eiteman, David K., author
Pearson, 2010
Buku Teks
Lincoln, Edmond E., author
McGraw-Hill, 1941
Buku Teks