@article{IVM_1974_2_a14, author = {V. I. Kholkin}, title = {The principal frequency of an inhomogeneous annular membrane}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {121--123}, publisher = {mathdoc}, number = {2}, year = {1974}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1974_2_a14/} }