slides

https://docs.google.com/presentation/d/1YGQZkwioDGaNaXt6RmaUSppes51vAbdd-d8ziUT-V0s/edit?usp=sharing

https://docs.google.com/presentation/d/1ErUrfm-sP0y2unWY-6fX_iFea_6gznEiGCp4XEiotJw