@article{ZNSL_1990_182_a5,
     author = {K. A. Makarov and S. E. Cheremshantsev},
     title = {Point interactions with internal structure as a limit of separable potentials},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {113--122},
     year = {1990},
     volume = {182},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1990_182_a5/}
}