&i;"as a tool for teaching undergraduate students and graduate students, &o;'Populus'&i; simply is the best in the world of its kind. Don continually is bringing it up-to-date with the most recent developments, and it is the kind of exciting and involving teaching tool which not only brings people to the cutting edge of contemporary research problems, but then encourages them to go beyond and do creative things of their own"&o; Sir Robert May, Oxford University.