Two of the images in the multimedia box are taken from the book Macroeconomics by Wynne Godley and Francis Cripps (Oxford University Press, 1983). The book is out of print and can’t even be seen at the publisher’s catalog. Used copies are available from various resellers in the internet. I got mine – and it looked brand new!
The two charts appear on the page 293 and models the potential scenario for stocks and flows from an assumed configuration of stocks and flows. Exports are assumed to rise exogenously by $20 and government expenditure is increased by $30, from $200 and $150 respectively.