@article{AIHPA_1977__27_4_387_0,
     author = {Courbage, M.},
     title = {Une classe d'invariants r\'eguliers en tant que limites asymptotiques ou moyennes ergodiques},
     journal = {Annales de l'institut Henri Poincar\'e. Section A, Physique Th\'eorique},
     pages = {387--405},
     publisher = {Gauthier-Villars},
     volume = {27},
     number = {4},
     year = {1977},
     mrnumber = {471794},
     language = {fr},
     url = {http://archive.numdam.org/item/AIHPA_1977__27_4_387_0/}
}