@article{EXMATH_2003_2003_1_a7,
     author = {Herzog, Gerd and Lemmert, Roland},
     title = {Soluciones positivas de sistemas de problemas de valor de frontera.},
     journal = {Extracta mathematicae},
     pages = {23-32},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EXMATH_2003_2003_1_a7/}
}