@article{SF_1997__54_2_135513,
     author = {N.C. jr. Bernardes},
     title = {A property of semigroups on metric spaces.},
     journal = {Semigroup forum},
     pages = {128--130},
     publisher = {mathdoc},
     volume = {54},
     number = {2},
     year = {1997},
     zbl = {0888.47019},
     url = {http://geodesic.mathdoc.fr/item/SF_1997__54_2_135513/}
}