Georgios C. Anagnostopoulos Michael Georgiopoulos Hypersphere ART and ARTMAP for Unsupervised and Supervised, Incremental Learning. 59-66 2000 IJCNN (6) http://csdl.computer.org/comp/proceedings/ijcnn/2000/0619/06/06196059abs.htm db/conf/ijcnn/ijcnn2000-6.html#AnagnostopoulosG00