Quantum field theory and quantum statistics : essays in honour of the sixtieth birthday of E.S. Fradkin, 2v.; v1. quantum statistics and methods of field theory, v2. models of field theory - Fradkin, E. S.; Batalin, I. A., ed; Isham, C. J., ed; Vilkovisky, G. A., ed (A. Hilger, 1987)