@article{TMF_1973_15_1_a2,
     author = {A. N. Vasil'ev and A. K. Kazanskii},
     title = {Convexity properties of {Legendre} transformations (variational methods in quantum field theory)},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {43--58},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1973_15_1_a2/}
}