Searching for multiple targets using Probabilistic Quadtrees. - Stefano Carpin; Derek Burch; Timothy H. Chung (IROS, 2011)

Variable Resolution Search with Quadrotors: Theory and Practice. - Stefano Carpin; Derek Burch; Nicola Basilico; Timothy H. Chung; Mathias Kölsch (J. Field Robotics, 2013)