Elmer Sperry : Inventor and Engineer, Paperback by Hughes, Thomas Parke, ISBN 0801847567, ISBN-13 9780801847561, Brand New, Free shipping in the US

Reprint of the Hopkins original, published in 1971, with no added material. Verso of the title page cites a cloth edition about which neither we nor the Jan. 1994 issue of Books in Print PLUS know anything. Annotation copyright Book News, Inc. Portland, Or.