Are there books on space explorations being a waste of money or not?

I'm doing a research paper on the topic of space explorations being a waste of money or not. At least two of my sources have to be books, and I was wondering if there are any books on this particular topic. If you could give me the titles of those books, that would be very helpful. Also, I'm thinking of interviewing an authoritative figure on this. Any ideas on whom I should interview?