@misc{Cayley_Arthur_(1821–1895)_Note_1889, author={Cayley Arthur (1821–1895)}, copyright={Public Domain}, journal={Mathematical papers}, address={Cambridge}, howpublished={online}, year={1889}, publisher={Cambridge University Press}, language={eng}, type={Text}, title={Note on the Porism of the In-and-circumscribed Polygon}, URL={http://www.rcin.org.pl/impan/Content/122051/PDF/WA35_149111_12807-2_Art15.pdf}, }