@article{10_21136_CPMF_1949_109150,
     author = {Levinson, Norman},
     title = {Criteria for the limit-point case for second order linear differential operators},
     journal = {\v{C}asopis pro p\v{e}stov\'an{\'\i} matematiky a fysiky},
     pages = {17--20},
     publisher = {mathdoc},
     volume = {74},
     number = {1},
     year = {1949},
     doi = {10.21136/CPMF.1949.109150},
     mrnumber = {0032066},
     zbl = {0033.18102},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CPMF.1949.109150/}
}