Here is the Kiplinger article that outlines the stimulus check mailing schedule for paper checks. https://www.kiplinger.com/article/taxes/T054-C000-S001-when-will-i-get-my-stimulus-check-2020.html
Here is the stimulus check calculator I used in the video.
Here is the Forbes article citing the Washington Post as the source for the paper check schedule.
IRS Economic impact payments
Bank Routing Number Verification