@misc{_Bulletin_1980,
 volume={28},
 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, fre, rus},
 type={Text},
 title={Bulletin de lʾAcademie Polonaise des Sciences. Série des Sciences Mathématiques T. 28 (1980)},
}