origami
Huzita–Hatori axioms - Wikipedia
One-, Two-, and Multi-Fold Origami Axioms Roger C. Alperin and Robert J. Lang
Modular origami – Polypompholyx
Modular origami | Origami Wiki | Fandom
Fold-and-cut theorem - Wikipedia
David Mitchell's Origami Heaven - Homepage (check out his page on hexaflexagons here or read more on flexagons)
Illustrated Guide to the Huzita-Hatori Origami Axioms - made by me! in college. Click to download the full PDF with ALL the axioms