Kosuke Hashimoto Kiyoko F. Aoki-Kinoshita Nobuhisa Ueda Minoru Kanehisa Hiroshi Mamitsuka A new efficient probabilistic model for mining labeled ordered trees. 177-186 2006 conf/kdd/2006 KDD http://doi.acm.org/10.1145/1150402.1150425 db/conf/kdd/kdd2006.html#HashimotoAUKM06