@article{IVM_1982_6_a18,
     author = {L. K. Orlik and M. A. Rutman},
     title = {Exponential indices of solutions of ordinary linear differential equations with periodic coefficients},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {80--81},
     year = {1982},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1982_6_a18/}
}