@article{TMF_1970_5_1_a13,
     author = {N. M. Plakida},
     title = {Decoupling of two-time {Green's} functions and diagrammatic analysis},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {147--153},
     year = {1970},
     volume = {5},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1970_5_1_a13/}
}