edited by John Keep and Liliana Brisby
Frederick A. Praeger; George Allen and Unwin, 1964
Buku Teks SO
Hall, Kermit L.
Oxford University Press, 1989
Buku Teks
Husna Abbas, Nooral Zeila Junid, Khairiyah Abdul Muttalib, Rohana Mohd Johari
Ministry of Health, 2001
Buku Referensi
Alexandrova, Vera
Doubleday, 1963
Buku Teks SO
Rauch, Georg von
Frederick A. Preager , 1957
Buku Teks SO