1. 〈http://pascallin.ecs.soton.ac.uk/challenges/voc/〉.
2. 〈http://research.microsoft.com/en-us/projects/objectclassrecognition/〉.
3. 〈www.ipb.uni-bonn.de/projects/etrims_db/〉.
4. 〈www.msri.org/people/members/eranb//
5. 〈www.outex.oulu.fi/index.php?page=scenes〉.