Moore, John A.
Macmillan Publishing Company, 1985
Buku Teks
Moore, Harry T.
Thames & Hudson, 1988
Buku Teks
Roberts, John G.
Franklin Watts, 1971
Buku Teks
Roberts, Larry S.
McGraw-Hill, 2000
Buku Teks
Spykman, Nicholas John
York Harcourt Brace , 1942
Buku Teks