Eckersley, C. E. (Charles Ewart), 1892-1967, author
Longmans, Green and Co., 1953
Buku Referensi
Srinivasan, S., author
1987
Buku Teks
Slapper, Gary, author
Cavendish Publishing Limited, 2000
Buku Teks
Buku Teks
Crabb, George, author
Grosset & Dunlap, 1945
Buku Referensi