Welch, Gita Honwana
Yetd Books, 1990
Buku Teks
Callow, Duncan
Chischester, 1995
Buku Teks
Robson, William Alexander, 1895-1980, author
Stevens & Sons Limited, 1951
Buku Teks
Murphy, Jefrie G., author
D. Reidel Publishing Company, 1979
Buku Teks
Heyde, Wolfgang
C.F. Muller Juristischer Verlag, 1999
Buku Teks