Deadlift - single leg stiff legged

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

Single leg standing stiff leg deadlift:

Stand on one leg - have the other foot off the ground, but kept roughly parallel with the leg doing the supporting. Bend the knee slightly, but that knee angle should not change during the exercise (get a partner to watch for this, as it will be tempting to do so!). Now bend at the waist, allowing the back to round and reach slowly towards the floor. If your range allows, touch the floor with the fingertips and return to the starting position.

The first time you do this you may find you are touching done with the non-supporting foot regularly to avoid falling over. This is ok, but in later workouts, try to minimise this. When you have mastered this exercise, touching of the ground by the non-supporting leg means terminate the set - this is your challenge.

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):

Single leg standing stiff leg deadlift:

Stand on one leg - have the other foot off the ground, but kept roughly parallel with the leg doing the supporting. Bend the knee slightly, but that knee angle should not change during the exercise (get a partner to watch for this, as it will be tempting to do so!). Now bend at the waist, allowing the back to round and reach slowly towards the floor. If your range allows, touch the floor with the fingertips and return to the starting position.

The first time you do this you may find you are touching done with the non-supporting foot regularly to avoid falling over. This is ok, but in later workouts, try to minimise this. When you have mastered this exercise, touching of the ground by the non-supporting leg means terminate the set - this is your challenge.

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 two 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....