How to Install Memory iMac 27-inch 5K (RAM Crucial 16GB) - YouTube
Don't Upgrade The RAM In Your New Apple iMac, Do This Instead
Install memory in an iMac - Apple Support
Factory Original 64GB (2x32GB) Memory Upgrade for 2020 & 2019 Apple iMac 27" w/Retina 5K Display & 2018 Apple Mac Mini DDR4 2666Mhz PC4-21300 SODIMM 2Rx8 CL19 1.2v RAM Adamanta at Amazon.com
The New 2017 iMac: Notes & Tidbits on RAM - The Mac Observer
Can you upgrade the RAM in the 27-inch iMac? | iMore