Kelly, Matthew
Ballantine Books, 2008
Buku Teks
King, Maurice H. (Maurice Henry), author
Univ. of Malaya, 1979
Buku Teks
Anastasia Arta Uli, author
Fakultas Psikologi Universitas Indonesia, 2019
UI - Tesis (Membership)
Dadzie, Stella
National Institute of Adult Continuing Education, 1993
Buku Teks
Routh , Thomas A
Charles C. Thomas , 1972
Buku Teks