@article{TMF_1974_18_1_a2,
     author = {O. I. Zavialov and P. B. Medvedev},
     title = {The~$R$-operation in the $\lambda\varphi^4$-theory as a~consequence of an~indefinite metric in the extended space of states (lowest orders)},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {27--38},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1974_18_1_a2/}
}