Again, sorry for taking so long to come back to you. Althought I understand what you are saying, Harry, I have to go with mgmueller - reference books and books with over 1000 pages (and a considerable amount of pictures, though not many), between others, tend to take up quite some space, but, as other kindle users have done, I think I'll use something as Dropbox, Box or SugarSync and hope it all goes for the better
DD