@article{NSJOM_1993_23_2a_30,
     author = {Ad\v{z}i\'c Nevenka},
     title = {Layer functions and 

 spectral approximation},
     journal = {Novi Sad Journal of Mathematics},
     pages = {351-362},
     publisher = {mathdoc},
     volume = {23},
     number = {2},
     year = {1993},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1993_23_2a_30/}
}