Read blogs from Piotr Wozniak, he did a lot of research on the subject and created supermemo. https://www.supermemo.com/english/company/wozniak.htm https://www

Read blogs from Piotr Wozniak, he did a lot of research on the subject and created supermemo. https://www.supermemo.com/english/company/wozniak.htm https://www.supermemo.com/english/company/wozniak.htm