@article{1102992294,
author = {Faris, William G.},
title = {The product formula for semigroups defined by Friedrichs extensions.},
journal = {Pacific J. Math.},
volume = {23},
number = {3},
year = {1967},
pages = { 47-70},
language = {en},
url = {http://dml.mathdoc.fr/item/1102992294}
}
Faris, William G. The product formula for semigroups defined by Friedrichs extensions.. Pacific J. Math., Tome 23 (1967) no. 3, pp. 47-70. http://gdmltest.u-ga.fr/item/1102992294/