Newman, Margaret A.
C.V. Mosby, 1986
Buku Teks
Colbert, Don, author
Siloam A Strang Company, 2007
Buku Teks
editors: Benjamin Ariel Marte, Alfred Merkle, Detlef Schwefel
Chaiporn Film Partnership, 1996
Buku Referensi
compiled and edited by Elaine Cumming
Jossey-Bass, 1970
Buku Teks
Blum, Hendrik L.
Thirth Party, 1983
Buku Teks