@article{10_1017_S0017089500030445,
     author = {Campos, R. G. and Avila, L. A.},
     title = {Some properties of orthogonal polynomials satisfying fourth order differential equations},
     journal = {Glasgow mathematical journal},
     pages = {105--113},
     year = {1995},
     volume = {37},
     number = {1},
     doi = {10.1017/S0017089500030445},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500030445/}
}