@misc{Cayley_Arthur_(1821–1895)_Note_1897,
 author={Cayley Arthur (1821–1895)},
 copyright={Public Domain},
 address={Cambridge},
 journal={Mathematical papers},
 howpublished={online},
 year={1897},
 publisher={Cambridge University Press},
 language={eng},
 type={Text},
 title={Note on the formula of trigonometry},
 URL={http://www.rcin.org.pl/impan/Content/125344/PDF/WA35_153805_12807-12_Art26.pdf},
}