@misc{Sylvester_James_Joseph_(1814–1897)_An_1909,
 author={Sylvester, James Joseph (1814–1897)},
 volume={3},
 copyright={Public Domain},
 address={Cambridge},
 howpublished={online},
 year={1909},
 publisher={Cambridge University Press},
 language={eng},
 title={An instantaneous graphical proof of Euler's theorem on the partitions of pentagonal and non-pentagonal numbers},
 type={Text},
 URL={http://www.rcin.org.pl/Content/162605/PDF/WA35_189997_11371-3_art-88.pdf},
}