(Riga)International Symposium on Organic Sulfure Chemistry International Symposium on Organic Sulfure Chemistry International Symposium on Topics in Surface Chemistry (Bangor)International Conference on Organic Sulphur Chemistry INternational Symposium on Topics in Surface Chemistry International Symposium on Fluorine Chemistry International Conference on Organic Sulphur Chemistry (Shrivenham)International symposium on sciontific software systems 1982 international symposium on circuits and syste 1983 international symposium on circuits and syste