Masahiro Hamasaki Hideaki Takeda Takuichi Nishimura Network analysis of massively collaborative creation of multimedia contents: case study of hatsune miku videos on nico nico douga. 165-168 2008 UXTV http://doi.acm.org/10.1145/1453805.1453838 conf/uxtv/2008 db/conf/uxtv/uxtv2008.html#HamasakiTN08