@article{10_4153_CJM_1966_018_2,
     author = {Cullen, C. G. and Hall, C. A.},
     title = {Classes of {Functions} on {Algebras}},
     journal = {Canadian journal of mathematics},
     pages = {139--146},
     year = {1966},
     volume = {18},
     number = {1},
     doi = {10.4153/CJM-1966-018-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1966-018-2/}
}