Metelka, Charles J.
Delmar, 1990
Buku Referensi
editor, Francois Vellas, Lionel Becherel; penerjemah, Indriati
Yayasan Obor Indonesia, 2008
Buku Teks
Boniface, Brian G
Routledge, 2016
Buku Teks
Foster, Dennis L.
RajaGrafindo Persada, 2000
Buku Teks
Foster, Douglas
Macmillan, 1985
Buku Teks