Im reading Loomis at the moment, one of the biggest masters about construction methods in drawing, I havent even reach the middle of the book and is a amazing, I totally recomend to read the book, im reading "Drawing the Head"
Here are some of my sketches and sidenotes I made while studying the book.
Y si sabes español, comparto en mi blog lo que he podido aprender de Loomis
https://lessaros.wordpress.com/2018/02/16/metodos-de-construccion-loomis/