Can you paper over existing paper

If the paper is not coming off the wall you should be able to paper over the existing paper.

You can, but I wouldn't. Steam off the old paper, repair the walls, then hang new paper.

http://homeguides.sfgate.com/hang-new-wallpaper-over-old-wallpaper-91229.html

You can. That said, it doesn't mean it's good to do. Best way is removing everything, stucco flat and smooth and then either paint or wallpaper. More work but better result. And in the long run, your wallcovering remains better.

Yes you can. As a child growing up in the 60's my mother had to have wallpaper. I can remember the paper lady coming and doing the job. She always papered over what was already there.

Oh yes you can, they did it all the time way back! Had to remove FOUR layers from bathroom in my 100+ year old house in Maine. If you decide to remove it use a steamer.

They will probably tell you to striip the old before putting on the new but in the old days, it was not unusual to find several layers of paper on any given wall. They make a steam pad (about 12" square) to fog off the old paper (check your rental store). I would say that going over old paper takes into account that any imperfections will come through on the new paper. Depends on your tolerance level for perfection.

The paper you put it over should be like a flat paint, no shine. If it does have shine, it may be one of the papers that you just can pull off the top layer and leave the backing behind. Paper over that.