Naoyasu Ubayashi Tetsuo Tamai Shinji Sano Yusaku Maeno Satoshi Murakami Aspect-Oriented and Collaborative Systems Metamodel Access Protocols for Extensible Aspect-Oriented Modeling. 4-10 2006 conf/seke/2006 SEKE db/conf/seke/seke2006.html#UbayashiTSMM06