Wernette, John Philip
Macmillan, 1964
Buku Teks
Hall, Ford P.
McGraw-Hill Book Company , 1949
Buku Teks
Anderson, Ronald A., author
South-Western Publishing Company, 1950
Buku Teks
Anderson, Ronald A., author
South-Western , 1981
Buku Teks
Maidment, Frederick, author
Prentice-Hall, 2000
Buku Teks