Teardown of New 4K 21.5-inch iMac Reveals Removable RAM and Modular CPU - MacRumors
iMac Retina 5K: Memory upgrade (RAM)
32GB 2X16GB NEMIX RAM Memory for Apple iMac 2017 27" Retina 5K - Newegg.com
HOW TO UPGRADE NEW 2017 IMAC RAM - YouTube
How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac
How To: Upgrade 2017 5k iMac RAM to 64GB & Saved $840 | 2018 - YouTube
Install memory in an iMac - Apple Support
iMac Intel 21.5" Retina 4K Display (2017) RAM and SATA Hard Drive Upgrade - iFixit Repair Guide
Amazon.com: 2017 Apple iMac with Intel Core i5 (21.5-inch, 8GB RAM, 1TB Storage) - Silver (Renewed) : Electronics
Used Apple iMac 27-inch (Retina 5K) 4.2GHZ Quad Core i7 (Mid 2017) MNED2LL/A-BTO - GainSaver
Amazon.com: OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S32P) : Everything Else
Buying a New iMac? Here's What You Need to Know About 2017 iMac RAM Upgrades
The New 2017 iMac: Notes & Tidbits on RAM - The Mac Observer