1. Burstall, R.: Program proving as hand simulation with a little induction. Proc. IFIP Congress 1974, Stockholm, pp. 308–312. Amsterdam: North Holland 1974
2. de Bakker, J.W., de Roever, W.P.: A calculus for recursive program schemes. In: Automata, Languages and Programming 1 (M. Nivat, ed.), pp. 167–196. Amsterdam: North Holland 1973
3. Devillers, R.E., Lauer, P.E.: A general mechanism for avoiding starvation with distributed control. Information Processing Lett. 7, 156–158 (1978)
4. Dijkstra, E.W.: Hierarchical ordering of sequential processes. Acta Informat. 1, 115–138 (1971)
5. Dijkstra, E.W.: A class of allocation strategies inducing bounded delays only. Proc. SJCC 1972, pp. 933–936. Montvale, N.J.: AFIPS Press 1972