It might be an issue of how broad you define spaced repetition. I think a lot of those cites use a fairly broad definition but no Anki/​Memosyth/​Supermeno is involved.
It might be an issue of how broad you define spaced repetition. I think a lot of those cites use a fairly broad definition but no Anki/​Memosyth/​Supermeno is involved.