Arrow, Kenneth J.
Yale University Press, 1963
Buku Teks
Babcock, Chester D.
Scott, Foresman, 1956
Buku Teks
Algie, Jimmy
kogan page, 1975
Buku Teks
Harcourt, Brace & World, 1970
Buku Teks
Reamer, Frederic G.
Columbia University Press, 1999
Buku Teks