Fisher, Sydney Nettleton
Routledge & Kegan Paul, 1959
Buku Teks
Routledge & Kegan Paul, 1958
Buku Teks
Sloan, A
Hutchinson , 1924
Buku Teks
Lenczowski, George
Cornell University Press, 1956
Buku Teks
Goldschmidt, Arthur
Westview Press, 1983
Buku Teks