Pusher: https://www.youtube.com/channel/UCoyqucxoFXDFnh3khD0rjUg
sentdex: https://www.youtube.com/channel/UCfzlCWGWYyIQ0aLC5w48gBQ
William Candilion: https://www.youtube.com/channel/UC806fwFWpiLQV5y-qifzHnA
Zeit: https://www.youtube.com/channel/UCLq8gNoee7oXM7MvTdjyQvA