https://docs.google.com/presentation/d/1eJbAz6_bgtN8kBDOWm3rUNQCFdw8MVpPvZ5dC49TOvU/edit#slide=id.p5
https://docs.google.com/document/d/1Igm85Q_rKSQ0t4rs-JgzpKB5iYqUaSz8bq-2xuGWqKg/edit