Single leg squat with back foot on bench

In 1999 (and on a few other occasions) I published and claimed copyright on this exercise description (bolding added now):

Single leg squat with back foot on bench

Some know this as a Bulgarian squat - with a difference. Face away from a normal height bench, and place your rear leg up on the bench. You can check your distance by having a relatively vertical shin throughout the movement. Place your hands on your head, and keep your chest and trunk vertical throughout.

Lower the body down by bending the knee of the lead leg until the knee of the back leg is almost on the ground.

We are going to use a speed of 515 - 5 sec lower, 1 second pause top and bottom, and 5 second lift. If you can do more than 10 reps, you can hold dumbbells in your hand. I don’t expect this to be necessary initially. Keep the knee aligned over the feet during the lower and the lift. You don’t need to do a warm up set - get straight into the work set.

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 squat with back foot on bench

Some know this as a Bulgarian squat - with a difference. Face away from a normal height bench, and place your rear leg up on the bench. You can check your distance by having a relatively vertical shin throughout the movement. Place your hands on your head, and keep your chest and trunk vertical throughout.

Lower the body down by bending the knee of the lead leg until the knee of the back leg is almost on the ground.

We are going to use a speed of 311 - 3 sec lower, 1-second pause top and bottom, and 1 second lift. If you can do more than 10 reps, you can hold dumbbells in your hand. Keep the knee aligned over the feet during the lower and the lift. You don’t need to do a warm up set - get straight into the work set.

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 seven 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....