Scyld Scefing wrote:-If you could tell me about other good books in this subject that would be great. Specially the best ones 'cause I couldn't afford for lots of them.
The Fortson book that Will recommends is
very good. However, his discussion of ablaut is brief.
Leonard Palmer's "Descriptive and Comparative Linguistics" has a good discussion of ablaut. This book is, I think, readily available used and it's inexpensive.
The most extensive discussion I know of is in Sihler's "New Comparative Grammar of Greek and Latin". But this book is a bit on the pricey side.
I also know of, but have not read, these journal articles, both from the late 1800s:
C.D. Buck - Some General Problems of Ablaut; American Journal of Philology Vol 17, No. 3
Maurice Bloomfield - The Ablaut of Greek Roots Which Show Variation between e and o; American Journal of Philology Vol 1, No. 3