@INPROCEEDINGS{baueran:pizka:iwpse03,
  AUTHOR =	 {Andreas Bauer and Markus Pizka},
  TITLE =	 {The Contribution of Free Software to Software Evolution},
  PUBLISHER =	 {IEEE Computer Society},
  BOOKTITLE =	 {Proceedings of the 6th International Workshop on
                  Principles of Software Evolution (IWPSE)},
  YEAR =	 2003,
  PAGES =        {170--183},
  MONTH =	 Sep,
  ADDRESS =      {Los Alamitos, CA},
  ISBN =         {0-7695-1903-2}
}