@misc{_Bulletin_1981,
 volume={29},
 number={11-12},
 editor={Polska Akademia Nauk.},
 editor={Państwowe Wydawnictwo Naukowe (1951–1992)},
 copyright={Rights Reserved - Restricted Access},
 address={Varsovie},
 howpublished={online},
 year={1981},
 publisher={Państwowe Wydawnictwo Naukowe},
 language={eng, rus},
 title={Bulletin de lʾAcademie Polonaise des Sciences. Série des Sciences Mathématiques T. 29 z. 11-12 (1981)},
 type={Text},
}