Unilateral and bilateral, and single and double/multi-joint exercises

In 1998 I wrote, published and claimed copyright on this concept (bolding added now):

My next and final step is to divide all the above into unilateral and bilateral, and single and double/multi-joint exercises

I was conducting research and I came upon the following exercise in a publication copyright claimed by another 'author' at a subsequent date (bolding added):

Exercises can be progressed as follows:

* Single joint to multiple joint

* Unilateral to bi-lateral.

And I said to myself: “That looks familiar!” So I cross-referenced it and I said to myself: “Wow! No wonder that looked familiar!”

And I came upon this wording another one more times by the same 'author' in different publications - in the absence of credits or references to the origin or permission to use from the original author (myself), and that the 'author' claimed copyright....