@article{ASNSP_1988_4_15_2_239_0,
     author = {Nussbaum, Roger D. and Cohen, Joel E.},
     title = {The arithmetic-geometric mean and its generalizations for noncommuting linear operators},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {239--308},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 15},
     number = {2},
     year = {1988},
     mrnumber = {1007399},
     zbl = {0756.47018},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1988_4_15_2_239_0/}
}