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I'm almost certain this book is not in the public domain. Maybe in some countries it is?
Before you get all excited about Pawn Power in Chess, did you check out in detail the preview on Google Books?
It's a pretty strange book, idiosyncratic to say the least, and there may be better ones out there to help you with pawn play.
So you might also look for Soltis's Pawn Structure Chess and Marovic's Understanding Pawn Play in Chess and Dynamic Pawn Play in Chess. All three of these are more modern treatments of the subject.
I would also recommend the soltis book, altough the notation takes a little getting used to.
oh, these Croatians can really make people happy