@article{TMF_1974_20_1_a3,
     author = {A. I. Nikishov},
     title = {$S$-matrix in quantum electrodynamics with external field},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {48--56},
     publisher = {mathdoc},
     volume = {20},
     number = {1},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1974_20_1_a3/}
}