Effective Action in Quantum Gravity: Buchbinder, I.L
Effective Action in Quantum Gravity: Buchbinder, I.L,Euclidean Quantum Gravity on Manifolds with Boundary,CP VIOLATION (CAMBRIDGE MONOGRAPHS ON PARTICLE PHYSICS, By I,Quantum Gravitation: The Feynman Path Integral Approach,Quantum Mechanics and Path Integrals: Richard P. Feynman