It's time for some studying again.
I bought a piece of George B. Bridgman's "The human machine", had it laying around for some time and finally found the time to actually make use of it. It's not a guide for drawing, rather than an explanation of how our body works and how to make it a little simpler for the artist.
Sadly quite some drawings are so rough or incomplete, it's hard to decipher them.
I daresay some are plainly wrong, so I had to google around and check on anatomical models to actually get it.