edited by Ronald Cohen and Elman R. Service
Institute for the Study of Human Issues, 1978
Buku Teks
Barnard, Alan, author
Cambridge University Press, 2011
Buku Teks
Pawson, Ivan G., author
John Wiley & Sons, 1977
Buku Teks
Baradat, Leon P., author
[publisher not identified], [date of publication not identified]
Buku Teks
Brace, C. Loring, author
Macmillan, 1969
Buku Teks