Bryson, Bill
Penguin Books, 1987
Buku Referensi
edited by Frank O. Colby
Thomas Y. Crowell, 1950
Buku Referensi
Peck, Anthony
MacMillan,, 1995
Buku Teks
Karen Sobel, editor
Libraries Unlimited, an imprint of ABC-CLIO, LLC, 2016
Buku Teks
Saunders, Joy
Berlitz, 1993
Buku Teks