Zhang, Y., D. R. Smith, and J. J. Simpson. “A 3-D Global FDTD Courant-Limit Model of the Earth for Long-Time-Span and High-Altitude Applications”. Applied Computational Electromagnetics Society Journal (ACES), vol. 39, no. 02, June 2024, pp. 123-9, doi:10.13052/2024.ACES.J.390205.