@article{MOMA_1980__90_177995,
     author = {G.A. Margulis},
     title = {Some {Remarks} on {Invariant} {Means.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {233--236},
     publisher = {mathdoc},
     volume = {90},
     year = {1980},
     zbl = {0425.43001},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1980__90_177995/}
}