@article{CMFD_2006_16_a2,
     author = {Ya. M. Dymarskii},
     title = {On topological properties of manifolds of eigenfunctions generated by a~family of periodic {Sturm--Liouville} problems},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {22--37},
     publisher = {mathdoc},
     volume = {16},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2006_16_a2/}
}