Gultom, Samuel, author
Greenwood Press, 1987
Buku Referensi
Compiled and edited by Dorothy Nyren Curley, Maurice Kramer, Elaine Fialka Kramer
Continuum, 1989
Buku Referensi
edited by Paula Geyh
Cambridge University Press, 2017
Buku Teks
edited by Margaret Drabble
Oxford University Press, 1998
Buku Referensi
edited by Margaret Drabble
Oxford University Press, 1985
Buku Referensi