Google various thesis papers and read them. I'm pretty sure there are a lot that are free on the internet. They're not necessarily the most interesting pieces of writing you will ever read (LOL), but you will learn academic writing. Don't read thesis papers in highly specialized fields, however, like chemical engineering (unless you understand chemical engineering, that is). Stick to history, psychology, sociology, etc. Here are academic papers by one of my favorite psychologists: http://oxford.academia.edu/BrianDEarp.