Leonidas Akritidis Dimitrios Katsaros Panayiotis Bozanis Identifying Influential Bloggers: Time Does Matter. 76-83 2009 Web Intelligence http://dx.doi.org/10.1109/WI-IAT.2009.18 conf/webi/2009 db/conf/webi/webi2009.html#AkritidisKB09