@article{BUMI_2012_9_5_2_a13,
     author = {Chernyavskaya, N. A. and Shuster, L. A.},
     title = {Integral {Inequalities} for the {Principal} {Fundamental} {System} of {Solutions} of a {Homogeneous} {Sturm-Liouville} {Equation}},
     journal = {Bollettino della Unione matematica italiana},
     pages = {423--448},
     publisher = {mathdoc},
     volume = {Ser. 9, 5},
     number = {2},
     year = {2012},
     zbl = {1260.34063},
     mrnumber = {2977257},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BUMI_2012_9_5_2_a13/}
}