@article{PIM_1981_N_S_29_43_a12,
     author = {Jovan D. Ke\v{c}ki\'c},
     title = {Four {Variations} on a {Theme} of {S.} {B.} {Pre\v{s}i\'c} {Concerning} {Semigroup} {Functional} {Equations}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {97 },
     publisher = {mathdoc},
     volume = {_N_S_29},
     number = {43},
     year = {1981},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1981_N_S_29_43_a12/}
}