If "Digital Electronics" by P. Raja is a specific textbook you're interested in, and you can't find it through standard channels, you might want to reach out directly to the publisher or the author (if possible) for assistance.
If "Digital Electronics" by P. Raja is a specific textbook you're interested in, and you can't find it through standard channels, you might want to reach out directly to the publisher or the author (if possible) for assistance.