@misc{_Prof.,
 copyright={Public Domain},
 howpublished={online},
 type={Image},
 title={Prof. Ludwik Birkenmajer},
 URL={http://www.rcin.org.pl/Content/77447/PDF/WA058_90707_Birkenmayer_L.pdf},
 keywords={Birkenmajer, Ludwik Antoni (1855-1929), academics, historians of science, physicists, astronomers, Jagiellonian University (Cracow, Poland)},
}