@article{709462,
      author = {Bobylev, N. A. and Burman, Yu. M. and Korovin, S. K.,},
      url = {http://library.usi.edu/record/709462},
      title = {Approximation procedures in nonlinear oscillation theory  [electronic resource] /},
      recid = {709462},
      pages = {1 online resource (284 pages)},
}