Some really fascinating designs in there. I might have to have a go at making the Quill!

Wouldn't have expected 40min video to fold an airplane: https://www.foldableflight.com/planes/lancer!

Nothing will ever replace Campbell Morris' Advanced Paper Aircraft Construction volumes 1-3 (or was it 4) for me, but this looks modern and ideal for young and aspiring ballistic cellulose aeronautical engineers.

Intermediate shows up twice for some reason.

Click on the first design, only way to learn how to fold is with a 10 minute YouTube video (always a bad sign when I see that magic number) with plenty of filler.