@misc{Sylvester_James_Joseph_(1814–1897)_On_1909,
 author={Sylvester, James Joseph (1814–1897)},
 volume={3},
 copyright={Public Domain},
 address={Cambridge},
 howpublished={online},
 year={1909},
 publisher={Cambridge University Press},
 language={eng},
 type={Text},
 title={On the number of fractions in their lowest terms whose numerators and denominators are limited not to exceed a certain number},
 URL={http://www.rcin.org.pl/Content/162594/PDF/WA35_189991_11371-3_art-84.pdf},
}