Wrist to Knee Curl ups

In 2000 (and on a few other occasions) I published and claimed copyright on this exercise description (bolding added now):

Wrist to knee Curl ups :

Technique the same as slow curl ups, however begin with arms extended and fingertips touching the knee. Slowly curl up, keeping arms extended until the wrist touches the knee. This is the end of the range for this exercise. Hold in this position and lower under control.

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):

Wrist to knee Curl ups :

Technique the same as slow curl ups, however begin with arms extended and fingertips touching the knee. Slowly curl up, keeping arms extended until the wrist touches the knee. This is the end of the range for this exercise. Hold in this position and lower under control.

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 description another one more times by the same 'author' in different publications.

I noted that the use of this description was 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....