@article{10_4153_CMB_2016_025_2,
     author = {Mih\u{a}ilescu, Mihai and Moro\c{s}anu, Gheorghe},
     title = {Eigenvalues of {\ensuremath{-}\ensuremath{\Delta}p} \ensuremath{-} {\ensuremath{\Delta}q} {Under} {Neumann} {Boundary} {Condition}},
     journal = {Canadian mathematical bulletin},
     pages = {606--616},
     year = {2016},
     volume = {59},
     number = {3},
     doi = {10.4153/CMB-2016-025-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-2016-025-2/}
}