1. Wikipedia, available from: https://en.wikipedia.org/wiki/Chuck_Hull (2016).
2. Wikipedia, avaliable from: https://en.wikipedia.org/wiki/S._Scott_Crump (2016).
3. ColorFabb, available from: http://colorfabb.com/specials (2016).
4. 3D PRINT CANAL HOUSE, available from: http://3dprintcanalhouse.com/construction-technique, (2016).
5. WISUN, available from: www.yhbm.com, (2016).