Hamilton, Edith, author
Crosset & Dunlap, 1942
Buku Teks
Treadwell, F.P., author
John Wiley & Sons, 1963
Buku Teks
Raffles, Thomas Stamford, author
Oxford University Press, 1982
Buku Referensi
Radhakrishnan, S. (Sarvepalli), 1888-1975, author
Macmillan, 1951
Buku Teks
Bremmelen, R.W. Van
Martinus Nijhoff, 1970
Buku Referensi