A classic...
For your convenience, I put some effort into finding a direct link for download of this book..
see
here.
However, be careful: this book may be a bit too concentrated on practical issues and problems.. it is accurate of course but it may lack the wide enough insight into mathematical way of thinking... Perhaps you need something more modern... it is a pity you can't read Russian (my assumption) - they used to have a lot of very cheap books (some of them were re-prints, sold for a fraction of price.. books written by
Demidovich were favourite reference at uni for lots of us.. I found the English translation
here)
This is just my feeling at the moment, I might be wrong.