digital_layer

Detail from Figure 3 in Krüger, M., J. Kinne, D. Lenz and Bernd Resch (2020), The Digital Layer: How Innovative Firms Relate on the Web, ZEW Discussion Paper No. 20-003, Mannheim, p. 7 (http://ftp.zew.de/pub/zew-docs/dp/dp20003.pdf).