Found in 2 comments on Hacker News
JKCalhoun · 2020-06-17 · Original thread
I remember that from the classic "Great International Paper Airplane Book". Seems it is on them cover even:

https://www.amazon.com/dp/0671211293?tag=duckduckgo-osx-20&l...

The 70's truly were a creative decade....

A seemingly related book is on archive.org, the helicopter appears to be on page 38:

https://archive.org/details/The_Great_International_Paper_Ai...

schlomie · 2011-04-25 · Original thread
Some of those look pretty similar to ones I recall making from this book as a child: http://www.amazon.com/Great-International-Paper-Airplane-Boo...

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