@article{EJDE_1995__1995_14_a0,
     author = {Allegretto,  Walter and Siegel,  David},
     title = {Picone's identity and the moving plane procedure},
     journal = {Electronic journal of differential equations},
     year = {1995},
     volume = {1995},
     number = {14},
     zbl = {0885.35004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1995__1995_14_a0/}
}