@misc{Richmond_Herbert_William_(1863–1948)_Note_1891-1892,
 author={Richmond, Herbert William (1863–1948)},
 volume={XXI},
 editor={Glaisher, James Whitbread Lee (1848–1928)},
 copyright={Public Domain},
 journal={The Messenger of Mathematics},
 address={London ;},
 address={Cambridge},
 howpublished={online},
 year={1891-1892},
 publisher={Macmillan and Co.},
 language={eng},
 title={Note on the sum of functions of quantities which are in arithmetical progression},
 type={Text},
 URL={http://rcin.org.pl/impan/Content/108940/PDF/WA35_87634_cz294-1892-t21_Art5.pdf},
}