Apple's 2012 iMac: Ready for its close-up (pictures) - CNET
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
iMac Intel 21.5" EMC 2544 Repair - iFixit
Memory Upgrades for iMac 27-Inch (2012 - Mid 2015)
Review: 21.5-inch 2012 iMac takes two steps forward, one step back | Ars Technica
21.5" iMac Has No User-Upgradable RAM; 27" Has Four Accessible RAM Slots - MacRumors
Apple iMac (Late 2012) review (21.5- and 27-inch) | Macworld
What Does It Take To Upgrade a 2012 iMac 21.5"?
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
Memory Upgrades for iMac 21.5-Inch 2012 - Late 2013
Install memory in an iMac - Apple Support
A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Apple's 27" iMac Late 2012 model. How to upgrade the ram to 16GB - YouTube
IMAC 21.5" LATE 2012 I5 8GB RAM 1 TB HDD GEFORCE GT 640M MOUNTAIN LION OS T4-C7 | eBay
2012 21.5-Inch Apple iMac Review: Slim, Sleek, And Stylish, But Far From Shallow | TechCrunch
Apple iMac 13,1 A1418 2012 Intel Core i5 3330S 2.70GHZ 8GB RAM NO Screen/HDD/OS | eBay
Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3L 1600MHz for Mac Book Pro(Early/Late 2011,Mid 2012), iMac(Mid 2011,Late 2012,Early/Late 2013,Late 2014,Mid 2015), Mac Mini(Mid 2011,Late 2012) MAC RAM at Amazon.com
A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com