Enis, Ben M., author
Goodyear, 1974
Buku Teks
Bearden, William O., author
McGraw-Hill, 2001
Buku Teks
Bearden, William O., author
McGraw-Hill, Irwin, 2007
Buku Teks
Clark, Fred E.
Macmillan, 1947
Buku Teks
Ryan, William T.
Dew Jones Irwin, 1980
Buku Teks