L.R. Ray, D. Brande, J.H. Lever, Estimation of Net Traction for Differential-Steered Wheeled Robots, J. Terramechanics Special Issue on Robotics, Volume 46, Issue 3, June 2009, Pages 75-87 (Abstract)

E. Trautmann, L. Ray, Mobility Characterization for Autonomous Mobile Robots Using Machine Learning, Autonomous Robot 30: 369-383, 2011, DOI 10.1007/s10514-011-9224-5 (Abstract)

L. Ray, Estimation of Terrain Forces and Parameters for Autonomous Robots, IEEE Trans. on Robotics, 25(3), 717-726, 2009. 10.1109/TRO.2009.201897 (Abstract)

L.R. Ray, D. Brande, J.H. Lever, Estimation of Net Traction for Differential-Steered Wheeled Robots, J. Terramechanics Special Issue on Robotics, 46, 75-87, 2009, doi:10.1016/j.jterra.2008.03.003 (Abstract)

J.H. Lever and L.R. Ray, Revised Solar-Power Budget for Cool Robot Polar Science Campaigns, Cold Regions Science and Technology, 52(2), 177-190, 2008 (Abstract)

L. Ray, A. Streeter, J. Lever, A. Price, Design and Power Management for a Solar-Powered ‘Cool Robot’ for Polar Instrument Networks, J. Field Robotics, 24(7), pp. 581-599, July 2007 (Abstract)