Books
R. Janicki, P. E. Lauer, Specification and Analysis of Concurrent Systems: The COSY Approach, EATCS Monographs on Theoretical Computer Science, Springer-Verlag, 1992, XXVI, 450 pp; softcover reprint in 2012.
R. Janicki, Outline of the Theory of Coroutines Vectors. Warsaw: PWN -- Polish Scientific Publ., 1980, 171 pp. (Monograph in Polish.)