Amazon.com: Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3 1333MHz PC3-10600 CL9 for Mac Book Pro (Early/Late 2011 13/15/17 inch), iMac(Mid 2010, Mid/Late 2011 21.5/27 inch), Mac Mini(Mid 2011) MAC RAM Upgrade :
Amazon.com: Timetec 32GB KIT(4x8GB) Compatible for Apple DDR3 1333MHz PC3-10600 CL9 for iMac (Mid 2010 27 inch, Mid 2011 21.5/27 inch) SODIMM Memory Module MAC RAM Upgrade for iMac 11,3 / iMac 12,1 / iMac 12, 2 : Electronics
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
Memory Upgrades for Apple iMac 2011 Up to 32GB
Install memory in an iMac - Apple Support
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
Install memory in an iMac - Apple Support
iMac Mid 2011 27" Upgrade Kit - Real Mac Mods
iMac Mid 2011 (21.5 – inch and 27 – inch) RAM Upgrade Dallas – Apple Mac Computer Repair Dallas , Laptop ,Desktop ,iMac ,MacBook iPhone iPad Data Recovery ,Virus
How to Upgrade Memory in a 21.5-inch or 27-inch iMac (Mid 2010) - YouTube
Memory RAM Upgrade for Apple iMac 27-inch Mid 2011 4GB/8GB DDR3 SODIMM | eBay
16GB -2x8GB Memory Ram Upgrade for 27" Apple iMac-12.2 Core i5 2.7GHz Mid 2011 | eBay
Maximum memory for 2011 iMac - Ask Different
Memory Upgrades for Apple iMac 2011 Up to 32GB
How to Upgrade iMac RAM (21.5" and 27" Aluminum): EveryMac.com
New 16GB 4x4GB Memory Apple iMac (21.5 and 27-inch, Mid 2011) PC3-10600
Adamanta 16GB (2x8GB) Apple Memory Upgrade DDR3L 1600MHz SODIMM Compatible for iMac (Mid 2011, Late 2012, Early/Late 2013, Late 2014, Mid 2015), MacBook Pro (Early/Late 2011, Mid 2012), Mac Mini at Amazon.com