@article{MAN_1994__300_2_165268,
     author = {W. Hansen and A. Boukricha},
     title = {Martin boundary for {Schr\"odinger} operators with singularity.},
     journal = {Mathematische Annalen},
     pages = {573--588},
     publisher = {mathdoc},
     volume = {300},
     number = {2},
     year = {1994},
     zbl = {0821.31004},
     url = {http://geodesic.mathdoc.fr/item/MAN_1994__300_2_165268/}
}