1. von Ahn, L.: Games with a purpose. Computer 39(6), 92–94 (2006)
2. Bird, S., Liberman, M.: Annotation graphs as a framework for multidimensional linguistic data analysis. In: Proceedings of the Workshop ”Towards Standards and Tools for Discourse Tagging”, Association for Computational Linguistics, pp. 1–10 (1999),
http://xxx.lanl.gov/abs/cs.CL/9907003
3. Broeder, D., Kemps-Snijders, M., Uytvanck, D.V., Windhouwer, M., Withers, P., Wittenburg, P., Zinn, C.: A data category registry- and component-based metadata framework. In: Calzolari, N., Choukri, K., Maegaard, B., Mariani, J., Odijk, J., Piperidis, S., Rosner, M., Tapias, D. (eds.) Proceedings of the 7th International Conference on Language Resources and Evaluation (LREC), European Language Resources Association (ELRA), Valletta, Malta, pp. 43–47 (2010)
4. Chamberlain, J., Poesio, M., Kruschwitz, U.: Phrase Detectives: A Web-based collaborative annotation game. In: iSemantics (2008)
5. Clark, H.H.: Bridging. In: Johnson-Laird, P.N., Wason, P.C. (eds.) Thinking: Readings in Cognitive Science, pp. 411–420. Cambridge University Press, Cambridge (1977)