(1972). Asimov's guide to science. New York: Basic Books, Inc.
Dyfyniad Arddull ChicagoAsimov's Guide to Science. New York: Basic Books, Inc, 1972.
Dyfyniad MLAAsimov's Guide to Science. New York: Basic Books, Inc, 1972.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.