1. https://www.weforum.org/agenda/2016/06/what-is-disruptive-innovation/
2. https://www.forbes.com/sites/freddiedawson/2014/09/30/how-disruptive-is-3d-printing-really/#558daeab4e44
3. https://hbr.org/2015/12/what-is-disruptive-innovation
4. http://claytonchristensen.com/
5. Clayton Christensen, (1997) The Innovator’s Dilemma: When New Technologies Cause Great Firms to Fail, Harvard Business Review Press; 1stedition