Spies, W.H. Power machines N5/ W H Spies. - Bergvlei [South Africa]: Southern Book; 1987. - 157 pages.: illustrations; 25 cm. - Mactech Books. . ISBN: 9781868120468 Paperback (pbk) Subjects--Topical Terms: --Power (Mechanics)--Power machines--Steam engineering Dewey Class. No.: ST 621.4 SPIE