@misc{Cayley_Arthur_(1821–1895)_On_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={On the invariants of a linear differential equation},
 URL={http://www.rcin.org.pl/Content/125370/PDF/WA35_153906_12807-12_Art51.pdf},
}