Friedmann, Wolfgang
Stevens & Sons Limited, 1953
Buku Klasik
edited by Dennis M. Patterson
Blackwell, 1999
Buku Teks
edited by Dennis Patterson
Blackwell, 1996
Buku Teks
Romano, Santi, 1875-1947, author
Routledge, 2017
Buku Teks
Sinha, Surya Prakash, author
West Pub. Co., 1993
Buku Teks