@article{NSJOM_1989_19_1a_4,
     author = {Roos Hans-G\"org},
     title = {A uniformly convergent discretization 

 method for a singularly perturbed boundary value problem of the fourther 

 order},
     journal = {Novi Sad Journal of Mathematics},
     pages = {51-64},
     publisher = {mathdoc},
     volume = {19},
     number = {1},
     year = {1989},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1989_19_1a_4/}
}