I think it's the fifth? It is gold. Used it extensively during my first grow. My pops had a hand in it too. Credit due!
I'll find my other books. They're both really informative and have some older style techniques given they published date. Garage is a mess as I'm reorganizing/rethinking/rebuilding my flower room. I just looked around because the soil book has a great section on micorhizae. I'll add them when I find them.