@Article{         Lancaster_1964aa,
  author        = {Lancaster, P.},
  doi           = {10.1007/BF01386087},
  file          = {Lancaster_1964aa.pdf},
  issn          = {0029-599X},
  journal       = {Numerische Mathematik},
  langid        = {english},
  number        = {1},
  pages         = {377--387},
  publisher     = {Springer-Verlag},
  title         = {On eigenvalues of matrices dependent on a parameter},
  volume        = {6},
  year          = {1964}
}