I have a big problem with procrastination. I've received a lot of help by reading books and articles by Dr. Bill Knaus, who's helped a lot of people with motivation.

I have to read material on a regular basis or I slide backwards. Here's an article from his Psychology Today blog. You can probably find a lot more by doing an internet search on his name. This article is just a small sample of his work. I have several of his books that I dip into whenever I start sliding backwards. At the bottom of this article there's a list of other Psych Today articles by him.

Do This One Thing and Stop Procrastinating | Psychology Today