Authors: D P Hill; P A Reasenberg; A Michael; W J Arabaz; G Beroza; D Brumbaugh; J N Brune; R Castro; S Davis; D Depolo; W L Ellsworth; J Gomberg; S Harmsen; L House; S M Jackson; M J Johnston; L Jones; R Keller; S Malone; L Munguia; S Nava; J C Pechmann; A Sanford; R W Simpson; R B Smith; M Stark; M Stickney; A Vidal; S Walter; V Wong; J Zollweg Journal: Science Date: 1993-06-11 Impact factor: 47.728