by Barry R. Furrow ... [and others]
West Publishing, 1987
Buku Teks
edited by L. Lynn Hogue
An Aspen Publication, 1980
Buku Teks
Hammaker, Donna
Delmar Cengage Learning, 2011
Buku Teks
Sitorus, Ayu S. Theresia
2015
UI - Skripsi Membership
Garrett, Thomas M.
Prentice-Hall, 2001
Buku Teks SO