2013 iMac teardowns reveal SSD slots, soldered-in CPU in the 21.5” model | Ars Technica
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
iMac 2013 Model Ram Upgrade - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
NEMIX RAM 16GB Kit (2x8GB Upgrade) DDR3-1600 SODIMM PC3-12800 for Apple MacBook Pro Mid 2012 / iMac Late 2012 / iMac 2013, Late 2014, Mid 2015, Mac Mini Late 2012 at Amazon.com
Install memory in an iMac - Apple Support
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
Apple iMac 2013 (Late) 21.5-inch (iMac 14,3) SSD ,Ram & OSX Upgrades - ZD Laptop Service Centre
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
HOW I UPGRADED MY iMAC 21.5in Late 2013 MODEL (SSD & RAM UPGRADE) - YouTube
How to UPGRADE RAM in the (Mid 2017) 5K iMac & save $$$! - YouTube
iMac RAM Upgrade mixing different memory sticks: 27” iMac late 2013 - YouTube