The mathematical physics of rainbows and glories (2001) [pdf]

If you're at all interested in this stuff, Atmospheric Optics is a fantastic resource that illustrates and explains these phenomena with both depth and accessibility. Note that the menu on the left hides lots of layers.

https://www.atoptics.org.uk/halo/common.htm

https://www.atoptics.org.uk/halo/dogfm.htm

Super old school, love that it's still online.

137 pave pdf on rainbows and it's in black and white. Pretty upset about this :)