Hamilton, Walton
McGraw-Hill Book Company , 1938
Buku Teks
Shepherd, William G., author
Richard D. Irwin, 1979
Buku Teks
Backman, Jules
The Ronald Press Company, 1953
Buku Teks
Shepherd, Geoffrey S., author
Iowa State University Press, 1968
Buku Teks
Adams, Walter, 1922-1998
Macmillan, 1957
Buku Teks