OWC 16GB (2x8GB) ram Upgrade PC3-12800 DDR3L 1600MHz sodimm 204 Pin CL11 Memory Upgrade Kit Compatible with Late iMac, Mac Mini, and MacBook Pro Computer at Amazon.com
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com
Upgrading the Late 2011 MacBook Pro to 16 GB of RAM! - YouTube
A-Tech 16GB (2x8GB) RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
A-Tech 8GB RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010 27 inch