https://de.wikipedia.org/wiki/Input-Output-Analyse
https://en.wikipedia.org/wiki/Input%E2%80%93output_model
https://www.bea.gov/industry/input-output-accounts-data
http://www.sjsu.edu/faculty/watkins/inputoutput.htm
https://de.wikipedia.org/wiki/Energie-_und_Stoffstrommanagement