@article{IM2_1992_38_3_a5,
     author = {E. S. Sinaiskii},
     title = {Simultaneous approximation of the solution and its derivatives in a boundary value problem for a linear differential equation with polynomial coefficients},
     journal = {Izvestiya. Mathematics },
     pages = {553--573},
     publisher = {mathdoc},
     volume = {38},
     number = {3},
     year = {1992},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1992_38_3_a5/}
}