Shuster, Huddleston and Staufer 'C & O Power'; L. Beebe 'The Overland Limited' 1963; Beebe and C. Clegg 'The Trains We Rode' 1966, two volumes; Shaughnessy 'Delaware & Hudson' 1967; R. Sloan and Skowronski 'The Rainbow Route' 1976; and others of American interest