Ramaswamy, M.
Stanford University Press, 1956
Buku Teks
Walker, Mary M.
General Learning Press, 1974
Buku Teks
Lamparello, Adam
Routledge, 2017
Buku Teks SO
Stern, Robert L.
Bureau of National Affairs, 1969
Buku Teks
Cox, Archibald, 1912-2004
Oxford University Press, 1976
Buku Teks