@article{BASS_2010_35_1_a2,
     author = {M. Kosti\'c},
     title = {Perturbation theorems for convoluted $C$-semigroups and cosine functions},
     journal = {Bulletin de l'Acad\'emie serbe des sciences. Classe des sciences math\'ematiques et naturelles},
     pages = {25 - 47},
     publisher = {mathdoc},
     volume = {35},
     number = {1},
     year = {2010},
     url = {http://geodesic.mathdoc.fr/item/BASS_2010_35_1_a2/}
}