Carr, Chris J.
Blacstone Press , 1989
Buku Teks
editors, Marcus D. Flather, Deepak L. Bhatt, Tobias Geisler
Blackwell , 2013
eBooks
Underhill, H.C. (Harry Clay), 1858-1918
Bobbs-Merrill , [19--?]
Buku Klasik
McGraw-Hill, 2002
Buku Teks
Stern, Scott D.C.
McGraw-Hill , 2015
Buku Teks