@article{UZKU_2006_148_3_a8,
     author = {R. K. Mukharlyamov and A. A. Popov},
     title = {Spherically symmetric perturbations in a~spatially flat universe},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {109--115},
     publisher = {mathdoc},
     volume = {148},
     number = {3},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_2006_148_3_a8/}
}