Apple's new 'Assembled in USA' iMac a bear to upgrade, repair • The Register
Pre-Owned Apple iMac 21.5-inch Desktop "Core i5" 2.9 (Late 2013) 8GB Memory 1TB HDD ME087LL/A - Best Buy
How To Upgrade RAM on the Apple iMac 2012 - 2013 RAM Upgrade - 21.5 inch model - YouTube
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
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
Install memory in an iMac - Apple Support
SOLVED: Need more ram for iMac 21.5 late 2013 - iMac Intel 21.5" EMC 2638 - iFixit
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Install memory in an iMac - Apple Support
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
Teardown of New 4K 21.5-inch iMac Reveals Removable RAM and Modular CPU - MacRumors
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