@article{leonard:1982:oda,
    author = {Leonard, Douglas A.},
     title = {Orthogonal polynomials, duality and association schemes},
   journal = {SIAM J. Math. Anal.},
  fjournal = {SIAM Journal on Mathematical Analysis},
    volume = {13},
      year = {1982},
    number = {4},
     pages = {656–663},
      issn = {0036-1410},
     coden = {SJMAAH},
   mrclass = {42C05 (33A65)},
  mrnumber = {MR0661597 (83m:42014)},
mrreviewer = {C. L. Parihar},
       doi = {10.1137/0513044},
     zblno = {0495.33006}}