@misc{Cayley_Arthur_(1821–1895)_Note_1889,
 author={Cayley Arthur (1821–1895)},
 copyright={Public Domain},
 address={Cambridge},
 journal={Mathematical papers},
 howpublished={online},
 year={1889},
 publisher={Cambridge University Press},
 language={eng},
 title={Note on the Transformation of a Trigonometrical Expression},
 type={Text},
 URL={http://rcin.org.pl/impan/Content/122046/PDF/WA35_149092_12807-2_Art10.pdf},
}