@Article{SCI:Gui2003a, author = "J.E. Guilkey and J.A. Weiss", title = "Implicit Time Integration with the Material Point Method", journal = "International Journal for Numerical Methods in Engineering", volume = "57", pages = "1323--1338", year = "2003", url = "http://www.sci.utah.edu/publications/guilkey03/impmpm_FINAL.pdf", }