The method of functionals in the quantum theory of fields
by Yu. V. Novozhilov and A. V. Tulub ; with an introductory article, Equations with variational derivatives in problems of statistical physics and of quantum field theory, by N. N. Bogolyubov.
New York : Gordon and Breach, ©1961.
viii, 79 págs. ; 23 cm.
Serie: Russian tracts on advanced mathematics and physics ; v. 5
Originally published as: Metod functsionalov v kvantovoi teorii polya, Uspekhi Fizicheskikh Nauk LXI, 1, 53-102 (1957), [and] Uravneniya s variatsionnymi proizvodnumi v problemakh statisticheskoi fiziki i kvantivoi teorii polya, Vestnik Moskovskogo Universiteta 10, 115-124 (1955).
Reseña: MathSciNet, 25 #959