@article{10_4153_CJM_1970_058_x,
     author = {Kallman, Robert R.},
     title = {A {Problem} of {Gelfand} on {Rings} of {Operators} and {Dynamical} {Systems}},
     journal = {Canadian journal of mathematics},
     pages = {514--517},
     year = {1970},
     volume = {22},
     number = {3},
     doi = {10.4153/CJM-1970-058-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-058-x/}
}