Willock, Colin
Doubleday, 1964
Buku Teks
Gerardo R. Vasta, Hafiz Ahmed, editor
CRC Press, 2009
Buku Teks
Wilson, James A. (James Albert), 1929-, author
Macmillan, 1979
Buku Teks
Dillon, Lawrence S.
Macmillan Company, 1966
Buku Referensi
Pandey, B.N., author
Tata McGraw-Hill, 2012
Buku Teks