Moshe Koppel Navot Akiva Idan Dershowitz Nachum Dershowitz Unsupervised Decomposition of a Document into Authorial Components. 1356-1364 2011 ACL http://www.aclweb.org/anthology/P11-1136 conf/acl/2011 db/conf/acl/acl2011.html#KoppelADD11