@article{shivakumar:1999:dp,
    author = {Shivakumar, P. N. and Xue, Jungong},
     title = {On the double points of a {M}athieu equation},
   journal = {J. Comput. Appl. Math.},
  fjournal = {Journal of Computational and Applied Mathematics},
    volume = {107},
      year = {1999},
    number = {1},
     pages = {111–125},
      issn = {0377-0427},
     coden = {JCAMDI},
   mrclass = {34B30 (34L16 34L40 65L15)},
  mrnumber = {MR1698481 (2000c:34065)},
       doi = {10.1016/S0377-0427(99)00084-9},
     zblno = {0944.34063}}