Goodwin, Donald W., author
Oxford Univesity Press, 1979
Buku Teks
Artikel Jurnal
Levinson, Harry, author
Harvard University Press, 1972
Buku Teks
Major, Ralph H., author
W.B. Saunders, 1958
Buku Teks
Major, Ralph H., author
W.B. Saunders, 1964
Buku Referensi