Groff Conklin, Collier Books, 1962; Science Fiction Classics, Fall 1967; The Arbor House Treasury of Science Fiction Masterpieces, eds.
This publication includes works by Groff Conklin, originally released in 1962, which were later included in the Science Fiction Classics series in Fall 1967, as part of a larger anthology titled The Arbor House Treasury of Science Fiction Masterpieces.