McGraw-Hill encyclopedia of science & technology / Vol. 20 McGraw-Hilledited by S.P. Parker - 7th ed. - New York : McGraw-Hill, c1992. - Volume 20 ; ill. ; 26 cm. ISBN: 0079092063 LCCN: Subjects--Topical Terms: Technology encyclopedia LC Class. No.: Q121 / .M3 1992