@article{JMPA_1940_9_19_1-4_107_0,
     author = {Haag, Jules},
     title = {M\'ethode de calcul des oscillations m\'ecaniques ou \'electriques. {Application} aux filtres},
     journal = {Journal de Math\'ematiques Pures et Appliqu\'ees},
     pages = {107--120},
     publisher = {Gauthier-Villars},
     volume = {9e s{\'e}rie, 19},
     number = {1-4},
     year = {1940},
     zbl = {0024.37403},
     language = {fr},
     url = {http://archive.numdam.org/item/JMPA_1940_9_19_1-4_107_0/}
}