Masayuki Kumazawa Hironori Kamada Atsushi Yamada Hiroshi Hoshino Yahiko Kambayashi Mukesh K. Mohania Relationship among copyright holders for use and reuse of digital contents. 254-255 2000 ACM DL http://doi.acm.org/10.1145/336597.336688 db/conf/dl/dl2000.html#KumazawaKYHKM00