@article{10_4171_dm_41,
     author = {Marc A. Rieffel},
     title = {Metrics on states from actions of compact groups},
     journal = {Documenta mathematica},
     pages = {215--230},
     year = {1998},
     volume = {3},
     doi = {10.4171/dm/41},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/41/}
}