@misc{Cayley_Arthur_(1821–1895)_Note_1891,
 author={Cayley, Arthur (1821–1895)},
 volume={4},
 copyright={Public Domain},
 journal={Mathematical papers},
 address={Cambridge},
 howpublished={online},
 year={1891},
 publisher={University Press},
 language={eng},
 type={Text},
 title={Note on the curvature of a plane curve at a double point, and on the curvature of sufraces},
 URL={http://rcin.org.pl./Content/127862/PDF/WA35_155475_12807-4_Note-on-the-curvature.pdf},
}