Harder, Paul O
Allyn and Bacon , 1975
Buku Teks
edited by Denis Arnold
Oxford University Press, 1992
Buku Referensi
Routledge, 2016
eBooks
edited by Richard Parncutt and Gary E. McPherson
Oxford University Press, 2002
Buku Teks
Wayan Gede Yogananda Kesawa, author
Fakultas Psikologi Unversitas Indonesia, 2016
UI - Skripsi (Membership)