Flind, Colin, author
Routledge, 2018
Buku Teks
Taylor, Peter J., author
Longman, 1995
Buku Teks
Latz, Gil, author
John Wiley & Sons, 1996
Buku Referensi
by Richard M. Highsmith, Jr.... [et.al.]
Prentice-Hall, 1961
Buku Teks
Jones, Stephen B.
Rand McNally & Company, 1962
Buku Teks