Yayasan Budi Penyayang Malaysia
Tuttle Publishing, 2011
Buku Referensi
Lieberthal, Kenneth G., author
Stanford University Press, 1980
Buku Teks
Macmillan Publishing Co., 1974
Buku Teks
edited by Dora V. Smith
Macmillan, 1974
Buku Teks
Postema, Gerald J., author
Clarendon Press, 1986
Buku Teks