@article{MAN_1931__104_159462,
     author = {R.C. Young},
     title = {The algebra of many-valued quantities},
     journal = {Mathematische Annalen},
     pages = {260--290},
     year = {1931},
     volume = {104},
     zbl = {0001.01102},
     url = {http://geodesic.mathdoc.fr/item/MAN_1931__104_159462/}
}