Sachs, Albie
University of California Press, 1973
Buku Teks
Elisabeth Kals, Jurgen Maes, editors
[Springer-Verlag;;;, ], 2012
eBooks
Friedman, Lawrence M., 1930-
Russell Sage Foundation, 1994
Buku Teks
edited by William B. Sanders and Howard C. Daudistel
Praeger, 1976
Buku Teks
Jones, Mark
Elsevier, 2012
Buku Teks