How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
How to: 27-inch 5K iMac (2019) 128GB RAM Upgrade - Save $$$! - YouTube
A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
CMS 16GB (2X8GB) DDR3 12800 1600MHz Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I5 3.4 27-Inch (Late 2013) Me089Ll/A - A7 at Amazon.com
Late 2013 iMac review: Faster than before, but the gains over previous models are modest | Macworld
Amazon.com: 2013 Apple iMac with 3.2GHz Intel Core i5 (27-inch, 8GB 1TB Mac OS X) (Renewed) : Electronics
How to Upgrade Memory in a 27-inch iMac (Late 2012-2013) iMac13,2 and iMac14,2 - YouTube
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
SSD Upgrades for Apple iMac 27-Inch Late 2013 - 2019
Install memory in an iMac - Apple Support
Can you upgrade the RAM in the 27-inch iMac? | iMore
Apple iMac 27" Late 2013 A1419 Logic Board i5 3.2GHz 775M 1GB 661-7516 | MacKing