(1969). Catalog of books 1969. New York: Litton Educational Publishing.
Dyfyniad Arddull ChicagoCatalog of Books 1969. New York: Litton Educational Publishing, 1969.
Dyfyniad MLACatalog of Books 1969. New York: Litton Educational Publishing, 1969.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.