Heyne, Paul T., author
Science Research Associates, 1973
Buku Teks
Leftwich, Richard H., author
Rienhard and Winston, 1969
Buku Teks
Blaug, Mark, author
Cambridge University Press, 1987
Buku Teks
Enke, Stephen, author
Prentice-Hall, 1951
Buku Teks
edited by Arthur L. Grey and John E. Elliot
Houghton Mifflin, 1965
Buku Teks