I use Paradox 9 Power Programming by Prestwood. It has a lot of info for ObjectPAL programming.
For more info about forms, reports etc., I use a combination of Mastering Paradox 7 for Windows95 and Corel Suite 8 Bible. I have found the differences between the earlier versions of Paradox for Win95 and Paradox 9 to not be different enough to make these older books obselete. But the Paradox 9 book by prestwood is really good for objectPAL info.
Glenn