De Vries, Mary Ann
[Publisher not identified], 1978
Buku Teks
Boston: Houghton: 1993,
Buku Referensi
Mager, N. H.
Prentice-Hall, 1975
Buku Referensi
Bay Books, 1986
Buku Referensi
editor, Rom Harre, Roger Lamb
Blackwell Reference, 1983
Buku Referensi