@article{1183528619, author = {Freyd, Peter}, title = {The Grothendieck group for stable homotopy is free}, journal = {Bull. Amer. Math. Soc.}, volume = {73}, number = {6}, year = {1967}, pages = { 84-86}, language = {en}, url = {http://dml.mathdoc.fr/item/1183528619} }
Freyd, Peter. The Grothendieck group for stable homotopy is free. Bull. Amer. Math. Soc., Tome 73 (1967) no. 6, pp. 84-86. http://gdmltest.u-ga.fr/item/1183528619/