Novelty-based Incremental Document Clustering for On-line Documents. - Sophoin Khy; Yoshiharu Ishikawa; Hiroyuki Kitagawa (ICDE Workshops, 2006)

A Query Language and Its Processing for Time-Series Document Clusters. - Sophoin Khy; Yoshiharu Ishikawa; Hiroyuki Kitagawa (ICADL, 2008)

A Novelty-based Clustering Method for On-line Documents. - Sophoin Khy; Yoshiharu Ishikawa; Hiroyuki Kitagawa (World Wide Web, 2008)

Querying Topic Evolution in Time Series Document Clusters. - Sophoin Khy; Yoshiharu Ishikawa; Hiroyuki Kitagawa (Inf. Media Technol., 2009)