Reddit mentions of Learn Japanese From Etymology: Approach From Sound Symbolism

I think I found it and thought it would be useful here... wow this was a tough one. But the PDF (20mb) is in a less (apologies) "child-friendly" format but has the same content.
http://www.koto8.net/nihongo_learn.pdf

Img1: S-01; to suck; pdf page 52
Img2: K-01; to curve; pdf page 83
Img3: N-03; gluey; pdf page 10
Img4: T-05; to adhere; pdf page 75

It is from this book Learn Japanese From Etymology: Approach From Sound Symbolism by Watanabe Masamichi
https://www.amazon.co.uk/Learn-Japanese-Etymology-Approach-Symbolism-ebook/dp/B00WWYP1VA

This book is a compilation of Japanese-specific vocabulary. This book focuses only on pure Japanese vocabulary excluding Chinese vocabulary which is shown by the kanji. This book covers approximately 1,800 Japanese words in total, which 860 of them are explained with illustrations. It covers almost all Japanese words. The Book is classifying Japanese in the unique method. The consistent idea throughout the book is “there is a relationship between vocal sounds and meanings in the Japanese language”. The principle of Japanese word generation is shown. The former linguistic theory of origin was a hypothesis. At this book, vocabulary is classified on the basis of Japanese origin theory. It is useful actually, so the value of this theory will be demonstrated.

https://www.amazon.co.jp/Learn-Japanese-Etymology-Approach-Symbolism-ebook/dp/B00WWYP1VA