@misc{Volterra_Vito_(1860–1940)_Sul_1897,
 author={Volterra, Vito (1860–1940)},
 volume={Vol. 2, 1893-1899},
 copyright={Public Domain},
 address={Roma},
 journal={Opere matematiche : memorie e note / Vito Volterra},
 howpublished={online},
 year={1897},
 publisher={Accademia Nazionale dei Lincei},
 language={ita},
 type={Text},
 title={Sul principio di Dirichlet},
 URL={http://rcin.org.pl./Content/161780/PDF/WA35_195366_11086-2_23.pdf},
}