@article{MZ_1988__198_3_173919,
     author = {Hitoshi Kitada},
     title = {Fundamental {Solutions} and {Eigenfunction} {Expansions} for {Schr\"odinger} {Operators} . {I.} {Fundamental} {Solutions.}},
     journal = {Mathematische Zeitschrift},
     pages = {181--190},
     publisher = {mathdoc},
     volume = {198},
     number = {3},
     year = {1988},
     zbl = {0627.35073},
     url = {http://geodesic.mathdoc.fr/item/MZ_1988__198_3_173919/}
}