Part II reviews studies that are of particular importance in the context of this dissertation. As presented in part I, this dissertation takes the theoretical lens of social capital and looks at innovation communities as a means to organize boundary crossing innovation processes. In consequence, three literature streams are highly relevant: (1) The open innovation literature, which discusses boundary crossing innovation processes, (2) the innovation community literature, which looks at communities and their role with regard to innovation, and (3) the social capital literature, which provides the theoretical lens applied.