@article {mcninch03:MR1987019,
    AUTHOR = {McNinch, George},
     TITLE = {Faithful representations of {$\rm SL_2$} over truncated
              {W}itt vectors},
   JOURNAL = {J. Algebra},
  FJOURNAL = {Journal of Algebra},
    VOLUME = 265,
      YEAR = 2003,
    NUMBER = 2,
     PAGES = {606--618},
      OPTISSN = {0021-8693},
     CODEN = {JALGA4},
   MRCLASS = {20G05 (20C33)},
  optMRNUMBER = {1987019 (2004c:20077)},
MRREVIEWER = {Timo Neuvonen},
       OPTDOI = {10.1016/S0021-8693(03)00269-2},
       OPTURL = {http://dx.doi.org/10.1016/S0021-8693(03)00269-2},
}