@article{AIHPA_1985__43_2_181_0,
     author = {Davies, E. B.},
     title = {Criteria for ultracontractivity},
     journal = {Annales de l'I.H.P. Physique th\'eorique},
     pages = {181--194},
     publisher = {Gauthier-Villars},
     volume = {43},
     number = {2},
     year = {1985},
     mrnumber = {817534},
     zbl = {0589.35030},
     language = {en},
     url = {http://www.numdam.org/item/AIHPA_1985__43_2_181_0/}
}