1. L. Breiman, Probability, Addison-Wesley, Reading, Mass., 1968.
2. K. L. Chung, A Course in Probability Theory, Harcourt, Brace & World, New York, 1968.
3. W. Feller, An Introduction to Problem Theory and Its Applications, Wiley, New York, 1971.
4. D. Griffeath, Coupling Methods for Markov Processes, Cornell University, Ph.D. Thesis, 1976. (This thesis contains a good bibliography of the coupling literature.)