John Hartley [and others]
Rinehart and Winston, 1962
Buku Teks SO
Arif Rosyidin
Fakultas Psikologi Universitas Indonesia, 2018
UI - Skripsi Membership
Manaloe, Sylvana Uli Basa Evi Dame
Fakultas Psikologi Universitas Indonesia, 2013
UI - Tesis Membership
Holschuh, Louis W.
St. Martin's , 1988
Buku Teks SO
Wood, Nancy V.
McGraw-Hill, 1991
Buku Teks SO