@misc{Sylvester_James_Joseph_(1814–1897)_Note_1908,
 author={Sylvester, James Joseph (1814–1897)},
 copyright={Public Domain},
 address={Cambridge},
 howpublished={online},
 year={1908},
 publisher={Cambridge University Press},
 language={eng},
 type={Text},
 title={Note on an intuitive proof of the existence of twenty-seven conics of closest contact with a curve of the third degree},
 URL={http://www.rcin.org.pl/Content/115290/PDF/WA35_139221_11371-2_Art13.pdf},
}