Robson, William Alexander, 1895-1980
Stevens & Sons Limited, 1951
Buku Teks
Viano, Emilio C.
Nelson-Hall, 1975
Buku Teks
Wang, Lv
China Renmin University Press, 2015
eBooks
Amery, L.S.
Oxford University Press, 1953
Buku Teks
Corwin, Edward S.
William Sloane, 1949
Buku Teks