Where to sell old GCSE revision notes?

I sold my old school textbooks at car boot sales etc. Try using popular sites on the Internet or donate them to the charity shops that are located on the high street in your local area.

I've got another month until GCSE's are over and me and I've got a mound of flashcards/notes that I don't think myself anyone in my family will ever used. I could throw them away (burn some of them defo lol) but some are actually of good quality and I don't want to feel as if they're being wasted so I wanted to make a profit off them. Any ideas as to where I could sell them? Also, when would be the ideal time to sell them? Thanks!