@article{1183530830, author = {Chen, Kuo-Tsai}, title = {An algebraic dualization of fundamental groups}, journal = {Bull. Amer. Math. Soc.}, volume = {75}, number = {5}, year = {1969}, pages = { 1020-1024}, language = {en}, url = {http://dml.mathdoc.fr/item/1183530830} }
Chen, Kuo-Tsai. An algebraic dualization of fundamental groups. Bull. Amer. Math. Soc., Tome 75 (1969) no. 5, pp. 1020-1024. http://gdmltest.u-ga.fr/item/1183530830/