@article{IVM_1973_2_a13,
     author = {I. D. Cherkasov},
     title = {Transformation of second order linear equations},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {106--115},
     publisher = {mathdoc},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1973_2_a13/}
}