Downloads are free, but if you find them useful and helpful, we would appreciate any type of donations to the wilsoneducationalfoundation.org. There are instructions on how to donate or where to send a check. This would be much appreciated. The Wilson Educational Foundation helps needy students complete their studies. We presently have 5 scholars including one who will graduate this year with a degree in mathematics and we will sponsor him to get his PhD. We are preparing to sponsor a student to law school. Your donation is tax deductible.