@misc{Pack_D.C._The_1982, author={Pack, D.C.}, volume={34}, number={3}, copyright={Creative Commons Attribution BY 4.0 license}, address={Warszawa}, journal={Archives of Mechanics}, howpublished={online}, year={1982}, publisher={Polish Scientific Publishers IFTR}, language={eng}, language={pol}, language={rus}, title={The development of bivariational principles for the calculation of upper and lower bounds}, type={Text}, URL={http://rcin.org.pl/Content/69224/PDF/WA727_89088_P.262-Pack-The-development.pdf}, keywords={Mechanika stosowana - czasopisma [KABA]}, }