@article{1183419152, author = {Peirce, George}, title = {A new approximate construction for $\pi$}, journal = {Bull. Amer. Math. Soc.}, volume = {14}, number = {3}, year = {1907}, pages = { 166-167}, language = {en}, url = {http://dml.mathdoc.fr/item/1183419152} }
Peirce, George. A new approximate construction for $\pi$. Bull. Amer. Math. Soc., Tome 14 (1907) no. 3, pp. 166-167. http://gdmltest.u-ga.fr/item/1183419152/