U. Bretschneider, und J. Leimeister. Open Tourism: Open Innovation, Crowdsourcing and Co-Creation Challenging the Tourism Industry, Springer Berlin Heidelberg, (2016)
M. Gierczak, U. Bretschneider, P. Haas, I. Blohm, und J. Leimeister. Crowdfunding in Europe – State of The Art in Theory And Practice; FGF Studies in Small Business and Entrepreneurship, Springer Science + Business Media, Cham, (2015)