@misc{Sylvester_James_Joseph_(1814–1897)_On_1908,
 author={Sylvester, James Joseph (1814–1897)},
 copyright={Public Domain},
 address={Cambridge},
 howpublished={online},
 year={1908},
 publisher={Cambridge University Press},
 language={eng},
 title={On a problem in tactic which serves to disclose the existence of a four-valued function of three sets of three letters each},
 type={Text},
 URL={http://rcin.org.pl/Content/115332/PDF/WA35_139783_11371-2_Art47.pdf},
}