@MISC{SETFAM_1.MIZ,
  AUTHOR = {Padlewska, Beata},
  TITLE = {Families of Sets},
  DAY = {05},
  MONTH = {April},
  YEAR = {1989},
  ADDRESS1 = {Warsaw University\\Bia{\l}ystok},
  SUMMARY = {      The article contains definitions of the following concepts:
family of sets, family of subsets of a set, the intersection of a family
of sets. Functors $\cup$, $\cap$, and $\setminus$ are redefined for families of
subsets of a set.
Some properties of these notions are presented.}}

