Rich, Carole
Wadsworth and Cengage Learning, 2010
Buku Teks
Bromage, Mary C.
McGraw-Hill, 1984
Buku Teks
Brooks, Brian S.
Bedford/St. Martins,, 2002
Buku Teks
by Brian S. Brooks [and others]
Martins Press, 1992
Buku Teks
Lubis, Grace Arion Mangiring Rapmauli
Fakultas Ilmu Administrasi Universitas Indonesia, 2023
UI - Skripsi (Membership)