It doesn't matter. Anything he writes is good.
Anything Osterlind puts out is good. Osterlind's material is stuff that he uses and tests for up to 20 years sometimes before he puts it out. Today, mentalists create something and release it within a year (if even that long). I only read old material now as I find it 100x better than the junk that is now being released and is a much better value.
If you can find Dynamic Mysteries by Richard Osterlind, then pick that up. It usually goes for like $10.00 or so on auction sites as I believe it is now out of print.
Also, Theatre of the Mind by Barrie Richardson:
http://www.penguinmagic.com/specialorde ... hp?ID=2630
I don't have this book, but I constantly see it in the top five lists of almost every mentalist:
http://www.penguinmagic.com/specialorde ... hp?ID=3540