One of my pastimes in idle moments is looking through online repositories of academic dissertations for interesting topics. Today I came across a 2009 University of Pretoria thesis entitled: The development of right hand guitar technique with reference to sound production. I haven't come across the author, Gerrit Lukas Roos, in any other context and I haven't so far done more than skim through the work, but he seems to have written a very comprehensive article. He deals with historical aspects of plucked string instrument technique before the 19th century and and focusses attention on the the variety of ideas about guitar RH technique from Carulli, Giuliani, Sor and Aguado to the present day. It looks like a good read.
Google The development of right hand guitar technique with reference to sound production. and you'll easily find it.
Eric from GuitarLoot
Renaissance and Baroque freak; classical guitars by Lester Backshall (2008), Ramirez (Guitarra del Tiempo 2017),
Yamaha (SLG 130NW silent classical guitar 2014).