Kopp, Richard L.
Houghton Mifflin, 1975
Buku Teks
Simon & Schuster, 1999
Buku Teks
Cowan, Mary L.
Appleton-Century-Crofts, 1962
Buku Teks
Charmaz, Kathy, author
Sage , 2014
Buku Teks
Kaplan, Norman M., 1931-, author
Lippincott, Williams & Wilkins, 2002
Buku Teks