@article{1183530641, author = {Heil, Wolfgang}, title = {On $P^2$-irreducible 3-manifolds}, journal = {Bull. Amer. Math. Soc.}, volume = {75}, number = {5}, year = {1969}, pages = { 772-775}, language = {en}, url = {http://dml.mathdoc.fr/item/1183530641} }
Heil, Wolfgang. On $P^2$-irreducible 3-manifolds. Bull. Amer. Math. Soc., Tome 75 (1969) no. 5, pp. 772-775. http://gdmltest.u-ga.fr/item/1183530641/