Thistlethwaite, Frank, author
Cambridge University Press, 1955
Buku Teks
Kagan, Shelly, author
Yale University Press, 2012
Buku Teks
Kagan, Shelly, author
Yale University Press, 2012
Buku Teks
Butler, E. M.
Beacon Press, 1935
Koleksi Publik
Asimov, Isaac, author
Doubleday, 1964
Buku Referensi