Punpiti Piamsa-nga Nikitas A. Alexandridis Search Algorithms for Subdatatype-Based Multimedia Retrieval. 167-186 1999 26 Journal of Intelligent and Robotic Systems 2 http://dx.doi.org/10.1023/A:1008150831513 db/journals/jirs/jirs26.html#Piamsa-ngaA99