Higher order modeling of hysteresis in disk drive actuators. - Daniel Helmick; William C. Messner (CDC, 2003)

Simultaneous control of a precision linear stage in multiple lubrication modes with the complex lag. - Daniel Helmick; William C. Messner (ACC, 2008)

Describing function analysis of Dahl model friction. - Daniel Helmick; William C. Messner (ACC, 2009)