@article{SF_1996__53_2_135489,
     author = {S. Kantorovitz},
     title = {On {Liu's} analyticity criterion for semigroups.},
     journal = {Semigroup forum},
     pages = {262--265},
     publisher = {mathdoc},
     volume = {53},
     number = {2},
     year = {1996},
     zbl = {0865.47027},
     url = {http://geodesic.mathdoc.fr/item/SF_1996__53_2_135489/}
}