https://chandra.si.edu/graphics/resources/handouts/lithos/crab_litho.pdf URL: https://chandra.si.edu/graphics/resources/handouts/lithos/crab_litho.pdf...
https://chandra.si.edu/graphics/resources/handouts/lithos/snr_litho.pdf URL: https://chandra.si.edu/graphics/resources/handouts/lithos/snr_litho.pdf...
si.edu/graphics/resources/handouts/lithos/discoveries_litho.pdf URL: https://chandra.si.edu/graphics/resources/handouts/lithos/discoveries_litho.pdf...
URL: https://chandra.si.edu/graphics/resources/handouts/lithos/poster_b.pdf URL: https://chandra.si.edu/graphics/resources/handouts/lithos/poster_b.pdf...