@incollection {MR1046850,
    AUTHOR = {Kawski, Matthias},
     TITLE = {Controllability, approximations and stabilization},
 BOOKTITLE = {Computation and control ({B}ozeman, {MT}, 1988)},
    SERIES = {Progr. Systems Control Theory},
    VOLUME = {1},
     PAGES = {155--167},
 PUBLISHER = {Birkh\"auser Boston},
   ADDRESS = {Boston, MA},
      YEAR = {1989},
   MRCLASS = {93D15 (49E15)},
  MRNUMBER = {MR1046850},
}