@article{SF_1976__12_134175,
     author = {M. Putcha},
     title = {The archimedean graph of a positive function on a semigroup.},
     journal = {Semigroup forum},
     pages = {221--232},
     publisher = {mathdoc},
     volume = {12},
     year = {1976},
     zbl = {0328.20056},
     url = {http://geodesic.mathdoc.fr/item/SF_1976__12_134175/}
}