Adamanta 16GB 4x4GB Apple Memory Upgrade for Mid 2010 iMac 21.5" and 27" DDR3 1333Mhz PC3-10600 SODIMM 2Rx8 CL9 1.5v RAM
CMS 16GB (4X4GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core I3 3.06 21.5-Inch (Mid-2010) - A28 at Amazon.com
OWC a la Carte Upgrades for iMac, including eSATA, Memory, SSD option
Timetec Hynix IC 8GB Compatible for Apple DDR3 PC3-8500 1067MHz /1066MHz SODIMM Memory Upgrade for MacBook 13 Mid 2010, MacBook Pro 13 Mid 2010, iMac 27Late 2009, Mac Mini Mid 2010 (8GB) - Walmart.com
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET
What to do when your iMac won't turn on?
16GB -2x8GB Memory Ram Upgrade for 27" Apple iMac-11.3 Core i5 3.6GHz Mid 2010 | eBay
Install memory in an iMac - Apple Support
iMac RAM Models 11.3 (i5 and i7 only) to 12.2 (8GBx4) | MacMemory.com
iMac Mid-2010 27 inch (A1312) SSD and RAM disassembly and upgrade - Much FASTER! - YouTube
32.0GB OWC Memory Upgrade Kit For 2010-2011 Apple iMac