@MISC{MODCAT_1.MIZ,
  AUTHOR = {Muzalewski, Micha{\l}},
  TITLE = {Category of Left Modules},
  DAY = {12},
  MONTH = {December},
  YEAR = {1991},
  ADDRESS1 = {Warsaw University\\Bia{\l}ystok},
  SUMMARY = {We define the category of left modules over an associative
 ring.  The carriers of the modules are included in a universum. The
 universum is a parameter of the category.}}

