edited by Peter Warr
Panguin Books, 1978
Buku Teks SO
Gilmer, B. von Haller (Beverly von Haller), 1909-1994
McGraw-Hill, 1967
Buku Teks SO
Auerbach, Alan J.
Brown & Benchmark, 1996
Buku Teks SO
edited by P.J.D. Drenth ... [and others]
Wiley, 1984
Buku Teks
edited by Pieter J.D. Drenth, Henk Thierry, Charles J. de Wolff
Routledge, 1998
Buku Referensi