@misc{Sawicki_Ludwik_(1893–1972)_Pismo_1958,
 author={Sawicki, Ludwik (1893–1972)},
 volume={79},
 copyright={Creative Commons Attribution BY 3.0 PL license},
 journal={Spuścizna prof. Ludwika Sawickiego : teczki archiwalne},
 howpublished={online},
 year={1958},
 language={pol},
 title={Pismo z dnia 20. 3. 1958 roku},
 type={Text},
 keywords={Krzywicki, Ludwik (1859-1941). The works, editing and development of scientific publications},
}