Scott, Hal S.
Sweet & Maxwell,, 2008
Buku Teks
Vernon, Raymond, author
Prentice-Hall, 1981
Buku Teks
Vernon, Raymond, author
Prentice-Hall, 1972
Buku Teks
Porteous, David J., author
Avebury, 1995
Buku Teks
Cathcart, Charles D., author
Richard D. Irwin, 1982
Buku Teks