D. P. Sanderson R. Sharma Roman Rozin Siegfried Treu The Hierarchical Simulation Language HSL: A Versatile Tool for Process-Oriented Simulation. 113-153 1991 1 ACM Trans. Model. Comput. Simul. 2 http://doi.acm.org/10.1145/116890.116911 db/journals/tomacs/tomacs1.html#SandersonSRT91