DeLamater, John D.
Colorado Westview Press, 2014
Buku Teks
Ashford, Jose B.
Wadsworth, 2001
Buku Teks
Ashford, Jose B.
Cengage Learning, 2018
Buku Teks
Pines, Ayala
McGraw-Hill, 1993
Buku Teks
Baron, Robert A.
Heights Allyn and Bacon , 1991
Buku Teks