Six library books isn’t too bad, and I’m a fast reader, so you might be wondering why it takes six months to write an article. Here’s (most) of the rest of what I had to read while writing it.
Roughly a seven inch stack of journal articles, many of them with titles like this:

Pessimism Perpetuated: Real Wages and the Standard of Living in Britain during and after the Industrial Revolution
FYI: According to Google, a sheet of paper is approximately 0.0039 inches thick, meaning I read 1795 pages of material.