@misc{Cayley_Arthur_(1821–1895)_Theorems_1895,
 author={Cayley, Arthur (1821–1895)},
 copyright={Public Domain},
 address={Cambridge},
 journal={Mathematical papers},
 howpublished={online},
 year={1895},
 publisher={Cambridge University Press},
 language={eng},
 type={Text},
 title={Theorems in relation to certain sign-symbols},
 URL={http://rcin.org.pl/Content/135389/PDF/WA35_168127_12807-8_Art61.pdf},
}