1. Azencott, R.: Behavior of diffusion semi-groups at infinity. Bull. Soc. Math. (France) 102, 193–240 (1974)
2. Brezis, H.: Functional Analysis, Sobolev Spaces and Partial Differential Equations. Universitext. Springer, New York (2011)
3. Burago, D., Burago, Y., Ivanov, S.: A Course in Metric Geometry Graduate Studies in Mathematics, vol. 33. American Mathematical Society, Providence (2001)
4. Chen, Z. -Q., Fukushima, M.: Symmetric Markov Processes, Time Change, and Boundary Theory, London Mathematical Society Monographs Series, vol. 35. Princeton University Press, Princeton (2012)
5. Chung, K. L.: Markov Chains with Stationary Transition Probabilities, 2nd edn. Die Grundlehren der mathematischen Wissenschaften Band, vol. 104. Springer-Verlag New York, Inc., New York (1967)