@book{1991-watt-issac
,title={{Proceedings of the 1991 international symposium on symbolic and algebraic computation, July 15--17, 1991, Bonn, West Germany}}
,booktitle={{Proceedings of the 1991 international symposium on symbolic and algebraic computation, July 15--17, 1991, Bonn, West Germany}}
,editor={Stephen M. Watt}
,ISBN={0--89791--437--6}
,publisher={Association for Computing Machinery}
,address={New York}
,year={1991}
}