Jie Yang 0028 Alessandro Bozzon Geert-Jan Houben Harnessing Engagement for Knowledge Creation Acceleration in Collaborative Q&A Systems. 315-327 2015 UMAP https://doi.org/10.1007/978-3-319-20267-9_26 conf/um/2015 db/conf/um/umap2015.html#YangBH15