Graveson, R.H.
Sweet & Maxwell, 1969
Buku Teks
Humphrey, John, author
A.W. Sijthoff, 1978
Buku Teks
Nygh, PE.
Butterworth, 1984
Buku Teks
Scoles, Eugene F., author
West Publishing, 1967
Buku Teks
Reese, Willis L.M., author
Foundation Press, 1971
Buku Teks