Crucial - DDR3 - 8 GB: 2 x 4 GB - SO-DIMM 204-pin - 1333 MHz / PC3-10600 - CL9 - 1.35 / 1.5 V - unbuffered - non-ECC - for Apple iMac, Mac mini (Mid 2011), MacBook Pro (Early 2011, Late 2011) System Specific Memory - Newegg.com
Early 2011 MacBook Pro RAM Upgrade – Hack-the-Planet
upgrade - 32gb of RAM on a 2011 or 2012 15/17-inch MacBook Pro using Crucial's 16gb single DIMMs - Ask Different
Crucial 8 GB SO-DIMM 1333 MHz PC3-10600 DDR3 Memory (CT2K4G3S1339M) for sale online | eBay
How to upgrade your 2011 or 2012 Macbook Pro RAM (with Step-by-Step photos) – Amanda Xi
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
Crucial 16GB Kit (8GBx2) DDR3/DDR3L 1333 MT/s (PC3-10600) SODIMM 204-Pin Memory For Mac - CT2K8G3S1339M at Amazon.com
Macbook Pro RAM Kit- 4GB (2 x 2GB) for 2011 2012 A1278 A1286 13 15" inch Crucial 649528754219 | eBay
Macbook Pro 17-inch 2.4GHz i7 - 17" Macbook Pro
Early 2011 MacBook Pro RAM Upgrade – Hack-the-Planet