Elia,
The best book I found was Whil Hentzen's "Programming Visual FoxPro 3.0", ISBN 1-56276-325-3, published by Ziff-Davis Press in Emeryville, California. The publishing date was 1995 but you could email them to see if they might still have a copy. Good Luck!
Bob Tracy
Never engage in a battle of wits if you're only half armed.