@misc{Sears_Julian_Ducker_(1891-1970)_Bulletin,
 author={Sears, Julian Ducker (1891-1970)},
 copyright={Biblioteka Politechniki Gdańskiej},
 howpublished={online},
 publisher={Government Printing Office.},
 language={eng},
 type={czasopismo},
 title={Bulletin 751-G. Geology and oil and gas prospects of part of Moffat County, Colorado, and southern Sweetwater County, Wyoming},
 keywords={geologia, mineralogia, petrografia},
}