Multiplane related
McKean, J. et al., Strong gravitational lensing with the SKA
Oguri, M., Strong gravitational lensing of explosive transients
Narayan & Bartelmann, Lectures on Gravitational Lensing
Image simulations for gravitational lensing with SkyLens, Bologna Lens Factory
GLAMER, github, paper-part 1, paper-part2
lenstool