It's well known that Lucas had a ton of cultural influences on "Star Wars" - mostly cinematic (Kurosawa, etc..) but also literary (at the very least, Campbell).
There are many sources that list possible literary influences (including a Wikipedia article) but all of the ones I saw, merely rely on "element A is similar in Star Wars and XYZ, so it's an influence", without direct proof that the influence happened. What I'm interested in, are influences that are acknowledged by the creators (Lucas, Kazan, etc...), or people who were intimately involved with canon (Leeland Chee etc...).
What are the acknowledged literary influences on "Star Wars"?