Here’s the habit-building book referred to in the video.
Here is Gretchen Rubin’s free online assessment you can take to see what kind of a habit-builder you are.
Here’s a PDF for a little yelling tracker form to be used for the first few days of your yell-no-more focus month. If it helps you, great, print out a few. If this is overwhelming, just take mental notes or something. The point is to notice patterns.