@article{NSJOM_2001_31_2a_1,
     author = {E. Pap},
     title = {Extension of null-additive set functions on 

 algebra of subset},
     journal = {Novi Sad Journal of Mathematics},
     pages = {9-13},
     publisher = {mathdoc},
     volume = {31},
     number = {2},
     year = {2001},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_2001_31_2a_1/}
}