Asimov, Isaac, author
Grafton Books, 1990.
Buku Teks
Miller, Walter M.
Harper & Row , 1997
Buku Teks
Sagan, Carl, author
Simon and Schuster , 1985
Buku Teks
Webb, Sharon, author
Atheneum, 1984
Buku Teks
edited by Eric S. Rabkin
Oxford University Press, 1983
Buku Teks