Hölterhof, T., & Heinen, R..  (2014).  A Concept to Bridge Personal Learning Environments: Including a Generic Bookmarking Tool into a Social Learning Management Systems. The Journal of Literacy and Technology - Special Edition: Papers from the 2013 PLE Conference Personal Learning Environments: Learning and Diversity in Cities of the Future., 15(2), 94-116. gehalten auf der 05/2014. Abgerufen von http://www.literacyandtechnology.org/uploads/1/3/6/8/136889/th.pdf