2 citations to https://www.mathnet.ru/eng/emj62
  1. L. G. Valiullina, Kh. K. Ishkin, R. I. Marvanov, “Spectral asymptotics for fourth order differential operator with two turning points”, Ufa Math. J., 10:4 (2018), 24–39  mathnet  crossref  isi
  2. Kh. K. Ishkin, Kh. Kh. Murtazin, “Asymptotics for the eigenvalues of a fourth order differential operator in a “degenerate” case”, Ufa Math. J., 8:3 (2016), 79–94  mathnet  crossref  mathscinet  isi  elib