OWC 2.0GB PC10600 DDR3 1333MHz SO-DIMM Compatible with 2011 MacBook Pro, Mid 2010/2011 21.5" & 27" iMac Models, 2011 Mac Mini (OWC1333DDR3S2GB) at Amazon.com
OWC 8GB (2 x 4GB) PC12800 DDR3L 1600MHz SO-DIMMs Memory Compatible with 2011-2015 iMac, 2011-12 Mac Mini, and 2011-2012 MacBook Pro (Non-Retina Display) Models (OWC1600DDR3S08S) at Amazon.com
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
MacBook Pro 13" Unibody Early 2011 RAM Replacement - iFixit Repair Guide
How to upgrade the memory in a Non-Retina 15-inch MacBook Pro 2011-2016 MacBookPro8,1 MacBookPro9,1 - YouTube
Early 2011 MacBook Pro 15" 16 GB RAM & Hard Drive Upgrade - YouTube
4GB RAM MEMORY FOR APPLE MACBOOK PRO CORE I5 2.3 GHZ 13" EARLY 2011 DDR3 NEW!!! | eBay
16GB Kit 2X8GB DDR3 Memory for Apple MacBook Pro 13-inch Core i5 2.4GHz Late 2011 MD313LL/A A1278 SODIMM RAM (PARTS-QUICK Brand) at Amazon.com