iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
2GB DDR3 1333 SODIMM for Apple iMac (Mid 2010,2011, Late 2011), Mac Mi – Aplus Technology
NEMIX RAM 32GB (4x8GB Upgrade) DDR3-1333 PC3-10600 204-Pin SODIMM Memory for Apple MacBook Pro Early/Late 2011, iMac Mid 2010 27 inch 4-Core, iMac Mid 2011 21.5/27” , Mac Mini Mid 2011 at Amazon.com
16GB Kit 4x 4GB DDR3 SODIMM RAM 1333MHz For Apple iMac 2011 12,1 12,2 Memory RAM | eBay
iMac RAM for Model 11.2 to 12.2 | DDR3-1066MHz | 24GB | MacMemory.com
Memory Upgrades for Apple iMac 2011 Up to 32GB
How to Upgrade Memory in a 21.5-inch or 27-inch iMac (Mid 2010) - YouTube
iMac 21.5-inch Mid 2011 20G RAM and RAM Access Cover (Crucial and Elpida) on eBid United States | 218535744
New 16GB 4x4GB Memory Apple iMac (21.5 and 27-inch, Mid 2011) PC3-10600 at Amazon.com
iMac RAM for Model 11.2 to 12.2 | DDR3-1066MHz | 8GB | MacMemory.com
21.5” mid-2011 iMac wires? Finally trying to upgrade my RAM and these wires are blocking the slot — did get an iMac with poor build quality? What can I do? : r/mac
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac