The first one explains how to calm a young baby. Created by Dr. Harvey Karp, he explains that human babies 0-3 months are underdeveloped at birth compared to other mammals, so it helps to treat them like they are still in utero. These steps help calm a baby and create an in-utero experience. (1) DUDU Swaddle, (2) Turn on Side (3) Shush loudly in ear (4) Jiggle (as if still in womb) I have tried his techniques and they are pretty unreal! When combined work like a charm every time!