Apple iMac 27-inch (2019) review: Apple iMac 2019 is a millennial trapped in the body of a baby boomer - CNET
Timetec 16GB Compatible for Apple DDR4 2666MHz for Mid 2020 iMac (20,1 / 20,2) / Mid 2019 iMac (19,1) 27-inch w/Retina 5K Display, Late 2018 Mac Mini (8,1) PC4-21333 / PC4-21300 SODIMM MAC RAM Upgrade at Amazon.com
How to Upgrade/Replace the Memory in a 21.5-inch iMac (2019) iMac19,2 - YouTube
OWC Announces RAM Upgrades for New 27-Inch 5K iMacs - MacRumors
Memory Upgrades for 2019-2020 iMac 27-Inch - Up to 128GB
Install memory in an iMac - Apple Support
How to Install Ram on the 2019 27 inch iMac and which Ram to Buy? - YouTube
How to upgrade the 27-inch 5K iMac (2019) with a massive 128GB of RAM [Video] - 9to5Mac