Apple iMac 27-Inch With 5K Retina Display (2017) Review | PCMag
Memory Upgrades for 2017 iMac 27-Inch
Upgrading a 27-inch iMac 5K to 14 terabytes - Replacing the Fusion Drive with both a SSD and an harddisk
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
Install memory in an iMac - Apple Support
Apple iMac with Retina 5K Display (2017) review | Digital Trends
A-Tech 64GB (4x16GB) RAM for Apple iMac 2017 27 inch Retina 5K | DDR4 2400MHz SODIMM PC4-19200 2Rx8 1.2V 260-Pin SO-DIMM Memory Upgrade Kit at Amazon.com
iMac 5k 27" Full Upgrade (CPU, RAM, SSD and M.2 NVMe) - Step by Step Time-lapse. - YouTube
OWC Confirms New Low-End 27-inch iMac Can Be Fitted With 64GB RAM - MacRumors
Configure your own 27-inch Apple iMac (2017) at OWC