Us

https://en.wikipedia.org/wiki/Usability

Sites
https://www.usability.gov/
https://www.usertesting.com/
https://usabilityhub.com/
https://www.userlytics.com/
https://www.userfeel.com/

Tube / Slides
https://www.youtube.com/results?search_query=Usability
https://www.slideshare.net/search/slideshow?searchfrom=header&q=Usability

nts

https://www.nts.com/

Time

https://www.testingtime.com/

ask

https://www.askattest.com/