How to upgrade the RAM on the 27-Inch iMac (2020) | AppleInsider
Apple Upgrades iMac and iMac Pro: More Cores, More Graphics, More Memory
Timetec 32GB 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
Review: Apple's final Intel 27-inch iMac is going out with a bang | AppleInsider
How to upgrade the 27-inch 5K iMac (2019) with a massive 128GB of RAM [Video] - 9to5Mac