Thank you for the learning materials posted as pdf. They're really very useful. Just one question. I suppose there must be a reason why some pdfs don't allow editing and are blocked with a password. But does anyone have the passwords? I like to edit my pdfs, as probably you do too.
Sorry for this silly request. I was not able to find any remark on this topic.
Thank you for admitting me as a member of this site.
Best regards/Χαιρετίσματα,
Antonio