@article{10_4153_CJM_1985_025_0,
     author = {C\'ac, Nguy\^en Phuong},
     title = {The {Method} of {Upper} and {Lower} {Solutions} for {Some} {Nonlinear} {Boundary} {Value} {Problems} in {Unbounded} {Domains}},
     journal = {Canadian journal of mathematics},
     pages = {430--441},
     year = {1985},
     volume = {37},
     number = {3},
     doi = {10.4153/CJM-1985-025-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1985-025-0/}
}