@misc{Pysiak_Leszek_Semidirect,
 author={Pysiak, Leszek and Eckstein, Michał and Heller, Michał (1936- ) and Sasin, Wiesław (matematyka)},
 language={eng},
 title={Semidirect Product of Groupoids and Associated Algebras},
 type={Artykuł},
 keywords={Matematyka, Algebra},
}