@MISC{NECKLA_3.MIZ,
  AUTHOR = {Retel, Krzysztof},
  TITLE = {The Class of Series-Parallel Graphs. 
{P}art {III}},
  ACKNOWLEDGEMENT = {The author would like to thank Professor
Grzegorz Bancerek for many helpful conversations during
the preparation of this paper, which allowed me to publish
it and for aquainting me with new search engine in MML (MML Query).
I am also very grateful to Professor Andrzej Trybulec, Adam Naumowicz,
and Adam Grabowski for their valuable advice.},
  SECTION1 = {Preliminaries},
  SECTION2 = {Some Facts about Operations ``UnionOf'' and ``SumOf''},
  SECTION3 = {Theorems Relating to the Complement of Relational Structure},
  SECTION4 = {Another Facts Relating to Operation ``embeds''},
  SECTION5 = {Connected Graphs},
  DAY = {03},
  MONTH = {February},
  YEAR = {2004},
  ADDRESS1 = {University of Bialystok},
  SUMMARY = {This paper contains some facts and theorems
  relating to the following operations on graphs: union, sum, complement
  and ``embeds''. We also introduce connected graphs to prove
  that a finite irreflexive symmetric N-free graph is a finite
  series-parallel graph. This article continues the formalization
  of \cite{Thomasse}.}}

