Nadel, S.F. (Siegfried Frederick), author
The Free Press of Glencoe, 1964
Buku Teks
Hammond, Peter, author
Macmillan, 1978
Buku Teks
Tavistock Publications, 1968
Buku Teks
edited by Edwin Ardener
Tavistock , 1971
Buku Teks
Nadel, S.F. (Siegfried Frederick), author
Cohen & West, 1969
Buku Teks