How to Upgrade iMac Hard Drive or SSD 2012-2022: EveryMac.com
Apple 21-inch iMac, late 2013 review | TechRadar
Apple's New 21.5 Inch iMac Has Upgradeable Parts — That's a Huge Deal
HOW I UPGRADED MY iMAC 21.5in Late 2013 MODEL (SSD & RAM UPGRADE) - YouTube
Teardown of new 21.5-inch iMac surprisingly reveals user-upgradable RAM, modular CPU - 9to5Mac
How to upgrade RAM iMac late 2013 21.5inch - break & fix MOVIE - YouTube
16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz SODIMM PC3-12800 204-Pin SO-DIMM Max Memory Upgrade at Amazon.com
2013 iMac teardowns reveal SSD slots, soldered-in CPU in the 21.5” model | Ars Technica
iMac Intel 21.5" EMC 2638 Teardown - iFixit
New CPUs, faster Wi-Fi, same flaws: Apple's 2013 iMac reviewed | Ars Technica
Install memory in an iMac - Apple Support
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Install memory in an iMac - Apple Support
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
The Display - 21.5-inch iMac (Late 2013) Review: Iris Pro Driving an Accurate Display
Install memory in an iMac - Apple Support
16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late