Schwartz, Bernard, author
Pitman, 1950
Buku Teks
Mashaw, Jerry L, author
Thomson/West, 2009
Buku Teks
Wade, H. W. R.
Clarendon Press, 1971
Buku Teks
Schwartz, Bernard, author
Little, Brown & Co., 1991
Buku Teks
Wade, H.W.R.
Claredon Press, 1994
Buku Teks