Frank W. Geels - Technological transitions as evolutionary reconfiguration processes: a multi-level perspective and a case-study - Research Policy 31 (2002) 1257–1274 (you can find it on google)
Background Multi-level-Perspective
In this article the Multi-level-Perspective aproach is introduced and further explained using a case study on the transistion from sailing ships to steam vessels. I read this article for another course and thought the case study was really helpful in understanding the Multi-level-perspective and the concept of niches.