Editor by Ralph D. Casey
Louisiana State University, 1963
Buku Teks SO
edited by Herman Wasserman
Routledge, 2013
Buku Teks SO
Ahuja, B. N.
Surjeet Publications , 1993
Buku Teks SO
Nibras Nada Nailufar
2016
UI - Makalah dan Kertas Kerja
Levy, Leonard W.
Harper, 1963
Buku Teks SO