@misc{Bortnik_Tomasz_Two_1980, author={Bortnik, Tomasz}, volume={28}, number={9-10}, editor={Polska Akademia Nauk.}, editor={Państwowe Wydawnictwo Naukowe (1951–1992)}, copyright={Rights Reserved - Restricted Access}, address={Varsovie}, howpublished={online}, year={1980}, publisher={Państwowe Wydawnictwo Naukowe}, language={eng}, type={Text}, title={Two generator two relator acyclic group}, }