@article{AIHPA_1978__28_1_41_0, author = {Kr\'ee, Paul and R\k{a}czka, Ryszard}, title = {Kernels and symbols of operators in quantum field theory}, journal = {Annales de l'institut Henri Poincar\'e. Section A, Physique Th\'eorique}, pages = {41--73}, publisher = {Gauthier-Villars}, volume = {28}, number = {1}, year = {1978}, zbl = {0386.47015}, mrnumber = {482179}, language = {en}, url = {http://archive.numdam.org/item/AIHPA_1978__28_1_41_0/} }