This and the following eight drawings have sometimes been referred to as pages from the 'Blue Homework Notebook'. There is no evidence for a notebook of this description; the 'blue' may well refer to the colour of the drawings rather than the notebook. These pages are from a Red Notebook, and may even be one of the missing signatures from Red Notebook: Brera 1970-74. Although dated 1974 in the New York 1979-80 catalogue, they are now thought to be from 1973. Related works CGM 328, 382, 383