Frederick A, Praeger; George Allen and Unwin Ltd., 1964
Buku Teks SO
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
Alexandrova, Vera
New York Doubleday 1963
Buku Teks