@article{KUIPM_1990_a3,
     author = {N. P. Evlampiev and I. E. Filippov},
     title = {Periodic solution of a linear functional equation with variable coefficients},
     journal = {Issledovaniya po Prikladnoi Matematike i Informatike},
     pages = {46--50},
     publisher = {mathdoc},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUIPM_1990_a3/}
}