1. B method web site,
http://www.bmethod.com
2. Event-b and the rodin platform,
http://www.event-b.org
3. Fuzzytech home page (2012),
http://www.fuzzytech.com
4. Prevention of load sway by a fuzzy controller (2013),
http://people.clarkson.edu
5. Set operations (2013),
http://www.cs.odu.edu/~toida