Wagener, Albert M.
D. Van Nostrand Company, Inc., 1950
Buku Teks
Siegel, Arthur
McGraw-Hill Ryerson, 1983
Buku Teks
Keenleyside, Hugh Ll.
Alfred A. Knopf , 1952
Buku Teks
Masters, Donald C., author
D. Van Nostrand, 1958
Buku Teks
Creighton, Donald, author
Macmillan, 1977
Buku Teks