Dissertations
Have you written a dissertation or thesis as part of finishing your degree? A dissertation or thesis can be an excellent source for book ideas. You may simply adapt your dissertation or thesis and write it to a more commercial, public audience. Or, you might use it as a starting point for a closely related idea. It might simply lead to a similar idea with a few modifications. If you haven’t written one, you can use other people’s dissertations and thesis papers as a starting point to finding a nonfiction book idea.
Go to http://wwwlib.umi.com/dissertations and you can search for dissertations that have been written by others. Search and browse around and perhaps you will find something that catches your attention that could be reworked into a book. Also search on Google.com and you will find many dissertations, theses and papers. There are tons of papers out there, so start searching browsing for ideas.