Apple iMac 27" - Late 2012 Reviews, Pros and Cons | TechSpot
iMac (27-inch, Late 2012) - Technical Specifications
A-Tech 8GB Kit (2x4GB) 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
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Review: 27-Inch iMac 5K with i5 processor - 2012 on the outside, 2019 on the inside | AppleInsider