@article{AIHPA_1970__13_2_163_0,
     author = {Bertrand, J.},
     title = {On the decomposition of the tensorial product of two representations of the {Poincar\'e} group - {Case} with at least one imaginary mass},
     journal = {Annales de l'institut Henri Poincar\'e. Section A, Physique Th\'eorique},
     pages = {163--194},
     publisher = {Gauthier-Villars},
     volume = {13},
     number = {2},
     year = {1970},
     language = {en},
     url = {http://archive.numdam.org/item/AIHPA_1970__13_2_163_0/}
}