@article{10_4153_CJM_1999_029_6,
     author = {Paul, Annegret},
     title = {First {Occurrence} for the {Dual} {Pairs} {(U(p,} q), {U(r,} s))},
     journal = {Canadian journal of mathematics},
     pages = {636--657},
     year = {1999},
     volume = {51},
     number = {3},
     doi = {10.4153/CJM-1999-029-6},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1999-029-6/}
}