@article{RM_1967_22_2_a1,
     author = {A. D. Myshkis and L. \`E. \`El'sgol'ts},
     title = {Some results and problems in the theory of differential equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {19--57},
     publisher = {mathdoc},
     volume = {22},
     number = {2},
     year = {1967},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1967_22_2_a1/}
}