Tarr, Graham.
Wiley, 1973
Buku Teks
Situmorang, Gloria Natalina, author
Fakultas Psikologi Universitas Indonesia, 2005
UI - Tesis (Membership)
Levitt, Steven D., author
NY William Morrow, 2014
Buku Teks
Shure, Myrna B., author
McGraw-Hill , 2005
Buku Teks
Cummins, Denise D., author
Cambridge University Press, 2012
Buku Teks