@article{SJVM_2000_3_1_a4,
     author = {S. B. Sorokin},
     title = {Error bounds of two-sided approximations for the {Sturm--Liouville} problem},
     journal = {Sibirskij \v{z}urnal vy\v{c}islitelʹnoj matematiki},
     pages = {73--88},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJVM_2000_3_1_a4/}
}