Jason Krogman wrote with this inquiry:

"I'm looking for any good articles on turf / soil nutrition. My books are getting a little boring."

I recommended these:

• Soil Fertility and Turfgrass Nutrition 101 by Jim Baird
• Does the grass know the cost? by Zontek et al.
• Purchasing new products and technologies: an ethical and common sense approach by Bob Carrow
• Posts tagged "fertilizer" on this blog. There are more than 160 posts with the fertilizer tag, many including links to research results, videos, webinars, presentation slides, articles, etc.
• Understanding turfgrass nutrient requirements, by me