@ARTICLE{NUMBER01.MIZ,
  AUTHOR = {Naumowicz, Adam},
  TITLE = {Elementary Number Theory Problems. {P}art {I}},
  SECTION1 = {Problem 1},
  SECTION2 = {Problem 2},
  SECTION3 = {Problem 3},
  SECTION4 = {Problem 4},
  SECTION5 = {Problem 5},
  SECTION6 = {Problem 6 (due to Kraitchik)},
  SECTION7 = {Problem 7},
  SECTION8 = {Problem 8},
  SECTION9 = {Problem 9},
  SECTION10 = {Problem 10},
  DAY = {26},
  MONTH = {February},
  YEAR = {2020},
  ADDRESS1 = {Institute of Informatics\\University of Bia{\l}ystok\\ Konstantego Cio{\l}kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  SUMMARY = {In this paper we demonstrate the feasibility of formalizing
  {\em recreational mathematics} in Mizar drawing examples from
  W. Sierpinski's book ``250 Problems in Elementary Number Theory'' \cite{Sierpinski:1970}. The current work contains proofs of initial ten problems from the
  chapter devoted to the divisibility of numbers.
  Included are problems on several levels of difficulty.}
  }

@BOOK{Sierpinski:1970,
 AUTHOR={Sierpi{\'n}ski, Wac{\l}aw},
 TITLE={250 Problems in Elementary Number Theory},
 PUBLISHER={Elsevier},
 YEAR=1970}

