Hansen, A. H.
Routledge , 1965
Buku Teks
Koontz, Harold
McGraw-Hill, 1956
Buku Teks
Swerdlow, Irving
Frederick A. Praeger, 1975
Buku Teks
Hanson, A.H.
Oxford University Press, 1966
Buku Teks
Frank, Isaiah, editor
Md. Johns Hopkins University Press, 1980
Buku Teks