@misc{Richardson_George_Burr_(1872-1949)_Bulletin,
 author={Richardson, George Burr (1872-1949)},
 howpublished={online},
 publisher={Government Printing Office.},
 language={eng},
 title={Bulletin 829. Geology and coal, oil, and gas resources of the New Kensington Quadrangle, Pennsylvania},
 type={czasopismo},
 keywords={geologia, mineralogia, petrografia, węgiel, Pensylwania (Stany Zjednoczone ; stan)},
}