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
Review: 21.5-inch 2012 iMac takes two steps forward, one step back | Ars Technica
Upgrading RAM On The New 27-inch iMac Is Easy, Here's How | Cult of Mac
NEMIX RAM 32GB Kit (4x8GB 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
Late 2012 iMac becomes vintage/obsolete this month, but is eligible for pilot repair scheme - 9to5Mac
Install memory in an iMac - Apple Support
16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
What Does It Take To Upgrade a 2012 iMac 21.5"?
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
Timetec Hynix IC Apple 8GB DDR3L 1600MHz PC3L-12800 SODIMM Memory upgrade For MacBook Pro 13-inch/15-inch Mid 2012, iMac 21.5-inch Late 2012/ Early/ Late 2013 (8GB) - Walmart.com
Opened up 2012 21.5 iMac for SSD upgrade. | MacRumors Forums