00354nam a2200109Ia 4500008004100000082001600041100002900057245006200086260003600148300002100184490003900205260427b        |||||||| |||| 00| 0 eng d  a512bK14.IC  aKallen, W. L. J. Van der  aInfinitesimally central extensions of chevalley groupsb/  aBerlin:bSpringer-Verlag,c1973  avii, 147p. Index  aLecture notes in Mathematicsv 356