H.A.F.
a.k.a. Rusty Nails
There is some other grow talk before where I copied the URL - it's all good. But here is where they start talking about the paper. The gist is that if you top a plant before taking lots of clones they'll root faster. Once the apical dominance is shot the plant sends hormones and stuff everywhere else looking for a new center. Making the plant produce it's own growth hormones.