1. Błażej Kubiński Polish stemmer https://github.com/Tutanchamon/pl_stemmer Błażej Kubiński Polish stemmer https://github.com/Tutanchamon/pl_stemmer
2. Andrzej Białecki Stempel - Algorithmic Stemmer for the Polish Language 2004. http://getopt.org/stempel/ Andrzej Białecki Stempel - Algorithmic Stemmer for the Polish Language 2004. http://getopt.org/stempel/
3. Semi-automatic stemmer evaluation
4. Dawid Weiss Lametyzator - Stemming engine for Polish 2003. http://www.cs.put.poznan.pl/dweiss/xml/projects/lametyzator/index.xml Dawid Weiss Lametyzator - Stemming engine for Polish 2003. http://www.cs.put.poznan.pl/dweiss/xml/projects/lametyzator/index.xml