Accelerating Electrostatic Surface Potential Calculation with Multi-Scale Approximation on Graphics Processing Units. 
Ramu Anandakrishnan, Thomas R.W. Scogland, Andrew T. Fenley, John C. Gordon, Wu-chun Feng, Alexey V. Onufriev.
In Journal of Molecular Graphics and Modelling, 
28 904-910, 
April 2010.