Hilditch, D., Baumgarte, T. W., Weyhausen, A., Dietrich, T., Brügmann, B., Montero, P. J., et al. (2013). Collapse of nonlinear gravitational waves in moving-puncture coordinates. Physical Review D, 88(10): 103009, pp. 1-12. doi:10.1103/PhysRevD.88.103009.