TY  - JOUR
AU  - N. A. Potapkov
TI  - Perturbation theory with variational parameter. Inequalities and estimates for the free energy
JO  - Teoretičeskaâ i matematičeskaâ fizika
PY  - 1973
SP  - 407
EP  - 416
VL  - 15
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TMF_1973_15_3_a12/
LA  - ru
ID  - TMF_1973_15_3_a12
ER  -