@article{RM_1986_41_1_a6,
     author = {L. M. Berkovich},
     title = {The~Halphen problem on equivalence of ordinary linear differential equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {221--222},
     publisher = {mathdoc},
     volume = {41},
     number = {1},
     year = {1986},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1986_41_1_a6/}
}