@article{UFA_2018_10_4_a11,
     author = {Ya. Il'yasov and N. Valeev},
     title = {On  inverse  spectral problem  and  generalized {Sturm}  nodal theorem for nonlinear boundary value problems},
     journal = {Ufa mathematical journal},
     pages = {122--128},
     publisher = {mathdoc},
     volume = {10},
     number = {4},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UFA_2018_10_4_a11/}
}