JanAtheCPA
Beloved Grand Eagle
My "Pocket" newsletter roundup had this link, which is a single link on their site with a collection of multiple articles from all kinds of different sources about the physical and mental benefits of mindful breathing, and/or different ways to engage in the practice. Most of the articles should be pretty accessible, although some might have a paywall (for example if you've exceeded your NY Times quota of free articles, you might be blocked from that one).
https://getpocket.com/collections/can-you-really-improve-your-breathing-yes-you-can (Can Better Breathing Really Improve Your Health?)
https://getpocket.com/collections/can-you-really-improve-your-breathing-yes-you-can (Can Better Breathing Really Improve Your Health?)