@article{TMF_1972_13_2_a0,
     author = {Kh. D. Popov and D. Ts. Stoyanov and A. N. Tavkhelidze},
     title = {$SL(2,R)$ symmetry of dual two-particle amplitude},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {145--173},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1972_13_2_a0/}
}