Ken Mattsson Frank E. Ham Gianluca Iaccarino Stable Boundary Treatment for the Wave Equation on Second-Order Form. 366-383 2009 41 J. Sci. Comput. 3 http://dx.doi.org/10.1007/s10915-009-9305-1 db/journals/jscic/jscic41.html#MattssonHI09