Edwards, Allen L.
Appleton Century Crofts, 1957
Buku Teks
Busonowiwoho Sumotirto
Madjelis Ilmu Pengetahuan Indonesia, 1959
Buku Teks
Lily Salim, author
Fakultas Psikologi Universitas Indonesia, 2006
UI - Tesis (Membership)
Jaccard, James, author
Wadsworth, 1983
Buku Teks
Fallik, Fred
The Dorsey Press, 1983
Buku Teks