My approach for art until this point was rather simplistic and cartoonish, in spite of aiming for something close to realism; and even though you get to a decent representation of the human figure this way it's not even close to something real. For this reason I have been carrying for some time basic mistakes that came from defining a face in the same angles and with the same eyes. There are plenty of subtleties and details you can't get down on the paper the way I draw.
So I'm working to redefine all that, but I wanted to ask the people around here if they knew any books and approaches to this besides Loomis' and Bridgman's; and particularly one I found on this forums that covered the surface of the head in circles to render it (no idea, I can only remember the picture partially).
Thanks in advance.