https://www.youtube.com/watch?v=p0O1VVqRSK0#t=5m20s
EDIT: The part about estimates is here: https://www.youtube.com/watch?v=p0O1VVqRSK0#t=36m56s
https://www.youtube.com/watch?v=p0O1VVqRSK0#t=5m20s
EDIT: The part about estimates is here: https://www.youtube.com/watch?v=p0O1VVqRSK0#t=36m56s