@article{IM_1976__37_142434,
     author = {E. Christopher Lance},
     title = {Ergodic {Theorem} for {Convex} {Sets} and {Operator} {Algebras.}},
     journal = {Inventiones mathematicae},
     pages = {201--214},
     year = {1976},
     volume = {37},
     zbl = {0338.46054},
     url = {http://geodesic.mathdoc.fr/item/IM_1976__37_142434/}
}