Bailey, Sydney D.
William Brendon ans Son, 1952
Buku Teks
Arasartnam, Sinnappah
Prentice-Hall, 1964
Buku Teks SO
Trautz, F.M.
Munchen Muller 1926
Buku Teks
Amerasinghe, Anthony Ranjit Bevis
Lake House Investments, 1971
Buku Teks
Tresidder, Argus John
D. Van Nostrand, 1960
Buku Teks SO