https://docs.google.com/presentation/d/1M7XmNFgtRcDuXxXEtb3TMKWZptYO6FCCeoxq5_RUOsg/edit#slide=id.g91035a48d7_686_346

https://docs.google.com/presentation/d/1XgyTdHzQM1cQrv1YpZJuRGtMv6AE9j4h6Phdn4Fe8-c/edit#slide=id.g91035a48d7_686_346