Coulouris, G. F., Dollimore, J. & Kindberg, T. (2001). Distributed systems: Concepts and design (3rd Ed.). Reading, MA: Addison Wesley. (TSDAS Digital Library: QA76.9 D5Cou)

Fidge, C. (1991). Logical time in distributed computing systems. IEEE Computer, 24(8), 2833.

Kaashoek, M. F.(1993). Group communication in amoeba and its applications. Distributed System Engineering, 1(9), 4858.

Lamport, L. (1978). Time, clocks and the ordering of events in a distributed system. Communications of the ACM, 21(7), 55865.

Mattern, F. (1989). Virtual time and global states in distributed systems. In Proceedings Workshop on Parallel and Distributed Algorithms, 21526.

Tanenbaum, A. S. & van Steen, M. (2002). Distributed systems: Principles and paradigms. Upper Saddle River, NJ: Prentice Hall. (TSDAS Digital Library: QA76.9 D5Tan)