国際会議: [1] Mizuki Yamamoto, Masao Ohira, Yasutaka Kamei, Shinsuke Matsumoto, and Ken-ichi Matsumoto, "Temporal Changes of the Openness of an Oss Community: a Case Study of the Apache Http Server Community," In he Fifth International Conference on Collaboration Technologies 2009 (CollabTech 2009), pages 64--65, August 2009.