@article{700934,
     title = {Probability measures on non-commutative semigroups},
     booktitle = {General Topology and its Relations to Modern Analysis and Algebra},
     series = {GDML\_Books},
     publisher = {Academia Publishing House of the Czechoslovak Academy of Sciences},
     address = {Praha},
     year = {1962},
     pages = {[307]-310},
     mrnumber = {MR0173721},
     zbl = {0118.11601},
     url = {http://dml.mathdoc.fr/item/700934}
}

Schwarz, Š. Probability measures on non-commutative semigroups, dans General Topology and its Relations to Modern Analysis and Algebra, GDML_Books,  (1962), pp. [307]-310. http://gdmltest.u-ga.fr/item/700934/