< They won't last more than 20 years, sorry :) Depends. The older ones may not, the later one are on far better paper though still not low acid. That change started in the early 80s. My introduction to programming 1972 is still doing well considering the newsprint it's on. < Seriously, all the DEC processor and programming paperbacks I've come < accross are printed on highly acidic paper, almost newsprint quality. < They can be de-acidified, if it's not too late. Check by gently None the less if it's a thing your serious about preserving then proceed. Allison