COMMENTARY: What can masks do? Part 2: What makes for a good mask

Executive Order on Protecting the Federal Workforce and Requiring Mask-Wearing

Upgrade Your Face Mask: 5 Ways To Filter Out More Particles : Shots - Health News : NPR

PDF) Face Masks Against COVID-19: An Evidence Review

Why N95 masks are so effective and how to wear one - The Washington Post

CDC urges that people double mask or to wear masks that fit - The Washington Post

Frequently Asked Questions about Cloth Face Coverings

Does My Mask Protect Me Against Covid-19 If Others Don't Wear One? - The New York Times

Release of silver and titanium from face masks traded for the general population - ScienceDirect

COMMENTARY: What can masks do? Part 2: What makes for a good mask study — and why most fail