I have removed a lot of wallpaper of the years in my 1920's home. The last room I did had 5 layers of paper. And whatever that original glue was --who knows. The best tip I have found is buy a bottle of Downy Liquid Fabric Softener. I add about a cup to a buck of water. Then wash the paper generously with this solution. It will soften the paper and the GLUE! It is cheap, good for the hands and smells nice. Give it a try.