Install memory in an iMac - Apple Support
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Apple iMac 21.5" All-in-One Desktop Computer Core i5-4570R 2.7GHz 8GB RAM 250GB HDD Mac OS Mojave Late-2013 w/ Keyboard & Mouse
21.5 inch late 2013 iMac - RAM upgrade - Apple Community
Apple iMac 2013 (Late) 21.5-inch (iMac 14,3) SSD ,Ram & OSX Upgrades - ZD Laptop Service Centre
Install memory in an iMac - Apple Support
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
How to Upgrade iMac RAM: 2012-2022: EveryMac.com
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
iMac Intel 21.5" EMC 2638 Teardown - iFixit
New CPUs, faster Wi-Fi, same flaws: Apple's 2013 iMac reviewed | Ars Technica
16GB -2x8GB Memory Ram Upgrade 21.5" Apple iMac-14.1 Core i5 2.7GHz Late 2013 | eBay
HOW I UPGRADED MY iMAC 21.5in Late 2013 MODEL (SSD & RAM UPGRADE) - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Apple's new 'Assembled in USA' iMac a bear to upgrade, repair • The Register
820-3482-A) Logic Board - iMac 21.5″ A1418 (Late 2013)
iMac Intel 21.5" EMC 2545/2638/2742 (2013) Memory Maxxer RAM Upgrade Kit
A-Tech 16GB Kit (2x8GB) 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
16GB (2x8GB) 8GB RAM Memory Upgrade Apple iMac 21.5'' A1418 27''A1419 2012 2013 | eBay
Apple iMac 21.5" A1418 ME087LL/A 2013 Core i5 2.90GHz 8GB RAM 1TB HDD – Coretek Computers
The Display - 21.5-inch iMac (Late 2013) Review: Iris Pro Driving an Accurate Display
Apple A1418 iMac 21.5" 2013 3.1GHz Intel i7 16GB RAM 1TB HDD OS10.13.6
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
I got a FREE 2013 iMac 21.5 with internal upgrades including Samsung evo ssd and 16gigs of ram. Then used open legacy patcher to install Mac OS Venture 13.5 beta. : r/osx
Teardown of New 4K 21.5-inch iMac Reveals Removable RAM and Modular CPU - MacRumors
