@article{TMF_2012_170_3_a1,
     author = {S. P. Suetin},
     title = {An~analogue of {the~Hadamard} and {Schiffer} variational formulas},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {335--341},
     publisher = {mathdoc},
     volume = {170},
     number = {3},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_2012_170_3_a1/}
}