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
iMac RAM for Model 13.2 to 15.1| DDR3-1600MHz | 8GBx2 | MacMemory.com
How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac
Can you upgrade the RAM in the 27-inch iMac? | iMore
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Install memory in an iMac - Apple Support
How to Install Memory iMac 27-inch 5K (RAM Crucial 16GB) - YouTube
How to Upgrade | Install RAM in iMac 5K 27 inch mid 2015 from crucial - YouTube