Book stores in Vietnam, any suggestions?  

Oh yeah, there's a few bookstores in Vietnam. A google search shows around 4 or 5 different ones. You're bound to find something good. :) 

There is a bookstore in Hanoi that I often go to is Ca Chep bookstore. There are many kinds of books for different types of audiences and ages, it has 3 floors and is decorated very creatively, I also have some special memories here, I think you should go there and try it out.

I would like to recommend EBOOK in Gò Vấp District HCMC. There have a lot kind of book and also there is a cf shop too. They sell many lovely sourvenir that you can buy some