@article{GDZPPN002426439, title = {Positivity Improving Operators and Hypercontractivity.}, journal = {Mathematische Zeitschrift}, volume = {180}, year = {1982}, pages = {225-234}, zbl = {0472.47015}, url = {http://dml.mathdoc.fr/item/GDZPPN002426439} }
Borell, Christer. Positivity Improving Operators and Hypercontractivity.. Mathematische Zeitschrift, Tome 180 (1982) pp. 225-234. http://gdmltest.u-ga.fr/item/GDZPPN002426439/