Can`t remove books from digital editions

[#1]

I have three books in digital editions wich come back in the library after deleting.

When I delete the, they are gone.

After closing digital editions, and opening again, they are back.

How to delite them perminent??

[#2]

I have three books in digital editions wich come back in the library after deleting.

When I delete the, they are gone.

After closing digital editions, and opening again, they are back.

How to delite them perminent??