@misc{Cayley_Arthur_(1821–1895)_Solution_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={Solution of (a, b, c, d)= (a², b², c², d²)},
 URL={http://www.rcin.org.pl/Content/125376/PDF/WA35_154301_12807-12_Art57.pdf},
}