@article{NSJOM_1989_19_2a_13,
     author = {Surla 

 Katarina},
     title = {A quadratic spline 

 difference scheme for a self-adjoint boundarz value problem},
     journal = {Novi Sad Journal of Mathematics},
     pages = {139-147},
     publisher = {mathdoc},
     volume = {19},
     number = {2},
     year = {1989},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1989_19_2a_13/}
}