Apple's new 'Assembled in USA' iMac a bear to upgrade, repair • The Register
Install memory in an iMac - Apple Support
How to: Install Ram into a IMac 21.5 inch (2011:2012) - YouTube
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Timetec Hynix Ic Apple 16Gb Kit (2X8Gb) Ddr3L 1600Mhz Pc3L-12800 Sodimm Memory Upgrade For Macbook Pro13-Inch/15-Inch Mid 2012, Imac 21.5-Inch : Amazon.in: Computers & Accessories
OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
How to Upgrade/Install Memory in a 21.5-inch iMac (Late 2012– Mid 2014) iMac14,1 iMac14,3 - YouTube
2012 21.5-Inch Apple iMac Review: Slim, Sleek, And Stylish, But Far From Shallow | TechCrunch
Apple iMac (Late 2012) review (21.5- and 27-inch) | Macworld
How to Upgrade Memory in a 27-inch iMac (Late 2012-2013) iMac13,2 and iMac14,2 - YouTube
Review: 21.5-inch 2012 iMac takes two steps forward, one step back | Ars Technica
New 21-Inch iMac Won't Let Users Upgrade RAM Themselves, But 27-Inch iMac Will | Cult of Mac