The musty smell of paper is very hard to remove. You could try a method that has proved effective, for me, personally.
You cannot wash the book nor scrub the smell out of it without damaging the pages. Spraying deodorants or fragrance sprays will mostly corrode the pages also. So what can you do? Why don't you try Camphor.
What is Camphor?
Camphor is a waxy, flammable, white or transparent solid with a strong aroma.
Camphor has a very pleasant smell and most importantly, it readily sublimes to its vapor state, thereby leaving the pleasant smell around the air it sublimes too. You could keep camphor near the books and within a few days, it should absorb the smell and the book should be rid of the musty smell. You might have to replace the sublimed camphor with fresh ones, and do this multiple times. The musty smell will pertain, but it will not be so intense and should cease to bother you. Camphor is flammable, but it is not very volatile. So it causes no harm to the books by catching on fire. However, I would advice you to keep it away from direct sunlight.
Camphor needs fresh air to sublime into its vapor. So keep the books in a well aerated room. The fresh air should also help in removing the musty smell.
Also, you could try Incense Sticks.
They give out a very good aroma and is often used to remove unwanted smell off the air. But, they are not available everywhere. If you are in Asia, you will have no difficluty find either, as camphor and incense sticks are used extensively. The only drawback for the incense sticks in that, it must burn continuesly. This brings in the risk of the book being damaged, if they are kept too close to each other.
If you could get a few incense sticks and set them on one part of the room, away from the book, and also camphor around the book, the book should be rid of the musty smell in a while.
It will take a while to see the results, or rather smell the results. But it should work, give it a shot.