Apple iMac 21.5-inch and 27-inch (Late 2013) reviews | Macworld
Install memory in an iMac - Apple Support
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Apple iMac 21.5-Inch Core i5 (Late 2013) All in One Desktop PC - Core i5 (I5-4570R) 2.7GHz - 8GB RAM - 1 TB HDD - Intel Iris Pro 5200 1536MB Graphics - Full HD Display - macOS High Sierra
Late 2013 iMac review: Faster than before, but the gains over previous models are modest | Macworld
16GB -2x8GB Memory Ram Upgrade 21.5" Apple iMac-14.1 Core i5 2.7GHz Late 2013 | eBay
DIY SSD upgrade kit for late 2013-2019 iMac|iMac late 2013-2019 SSD with upgrade kit|Flexx Memory|Free UK Delivery
Amazon.com: OWC 2TB Aura Pro X2 NVMe SSD Upgrade Kit Compatible with Select 27" and 21.5" iMac Models (Late 2013 - Current) : Electronics
21.5-inch iMac (Late 2013) Review: Iris Pro Driving an Accurate Display
Install memory in an iMac - Apple Support
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Apple iMac (21.5-inch, Late 2013) - Intel Core i5-4570R - 8GB RAM - 500GB SSD | Stone Refurb
Apple iMac 21.5" Late 2013 A1418 Logic Board i5 2.9GHz 5200 1GB 1GB 66 | MacKing
Apple iMac 2013 (Late) 21.5-inch (iMac 14,3) SSD ,Ram & OSX Upgrades - ZD Laptop Service Centre