Bo Liu Jietao Zou Jie Zhang Tianguang Chu Long Wang Controllability of a Leader-Follower Dynamic Network with Interaction Time Delays. 468-473 2008 FSKD (5) http://dx.doi.org/10.1109/FSKD.2008.607 conf/fskd/2008-5 db/conf/fskd/fskd2008-5.html#LiuZZCW08