edited by Denton E. Morrison and Ramon E. Henkel
Aldine, 1973
Buku Teks
Briggs, Lawrence Palmer
The American Philosophical Society, 1951
Buku Teks
CRC press, 2020
eBooks
Hunt, Elgin F.
MacMillan, 1987
Buku Teks
Sumner, William Graham
New Haven Yale University Press, 1950
Buku Teks