~~30 Units~~ ~Paper used is 2:3 ratio rectangle.~ You can find a tutorial on how to cut square paper into proper size for this kusudama here - ... A tutorial on how to make the Whirlpool kusudama designed by Ekaterina
by Mr.Paper Crafts
by Ankhang Handmade
by Henry Phạm - Origami Tutorials
by Paper Kawaii - Origami Tutorials
by Arthur 3D origami
by 折り紙の時間 / Origami Time
by All About Craft Ideas