… books by Bruno Munari on drawing trees and drawing the sun. Online descriptions suggest they were written for children but I think what is meant is children of all ages. Unexpected finds as I walked through the library. Thank goodness I have a big backpack.
More information about Bruno Munari
Brainpickings on Munari: https://www.brainpickings.org/2012/11/22/bruno-munari-design-as-art/
drawing a tree: http://www.artbook.com/8887942765.html
drawing the sun: http://www.artbook.com/8887942773.html
Wikipedia on Munari: https://en.wikipedia.org/wiki/Bruno_Munari