@article{1102912801, author = {Helton, Jon C.}, title = {Product integrals and inverses in normed rings.}, journal = {Pacific J. Math.}, volume = {55}, number = {2}, year = {1974}, pages = { 155-166}, language = {en}, url = {http://dml.mathdoc.fr/item/1102912801} }
Helton, Jon C. Product integrals and inverses in normed rings.. Pacific J. Math., Tome 55 (1974) no. 2, pp. 155-166. http://gdmltest.u-ga.fr/item/1102912801/