1. Banwell, C.J.: Life expectancy of geothermal fields. Geother. Energy 2(7), 12–13 (1974)
2. Big Duck Games LLC: Flow free.
http://tiny.cc/ilzocz
3. Bitmango: Line puzzle.
http://tiny.cc/vpzocz
4. Bouman, J., Leppen, E.: Turmoil.
http://tiny.cc/vrzocz
5. Boyes, S.: Motherload.
http://www.xgenstudios.com/play/motherload