Not sure it could help other people, but still.

I tutor in 'statistical biology' a girl who might choose to go into math. About a week ago I gave her Thomas's Calculus and analytic geometry, pt. 1, and told her that as long as she can work through the exercises, the book is hers, but as soon as [the clock strikes midnight] she loses interest, she should return it.

She pounced at it, and said today that she's solved a few problems, although one of them she could not understand (it's in English, after all), so - baiting people with foreign, advanced, and most of all, privileged textbooks is a powerful tool:)