@article{10_4153_CJM_1973_131_2,
     author = {Promislow, David},
     title = {Semi-Metrics on the {Normal} {States} of a {W} {*-Algebra}},
     journal = {Canadian journal of mathematics},
     pages = {1238--1253},
     year = {1973},
     volume = {25},
     number = {6},
     doi = {10.4153/CJM-1973-131-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-131-2/}
}