@article{10_4007_annals_2005_162_919,
     author = {Vladimir Maz'ya and Mikhail Shubin},
     title = {Discreteness of spectrum and positivity criteria for {Schr\"odinger} operators},
     journal = {Annals of mathematics},
     pages = {919--942},
     publisher = {mathdoc},
     volume = {162},
     number = {2},
     year = {2005},
     doi = {10.4007/annals.2005.162.919},
     mrnumber = {2183285},
     zbl = {1106.35043},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4007/annals.2005.162.919/}
}