Varga, Csaba, author
Csaba Varga & Original Holders, 1994
Buku Teks
Maris, Cees, editor
Springer, 2011
eBooks
Rommen, Heinrich A.
Liberty Fund Indianapolis, 1998
Buku Teks
Amao, Olufemi, author
Routledge, 2019
Buku Teks
Sinha, Surya Prakash, author
West Pub. Co., 1993
Buku Teks