Apple MacBook Pro A1278 13" Early 2011 Logic Board 2.3ghz Core I5 for sale online | eBay
Step-By-Step Guide to Upgrade the Memory of an Early 2011 MacBook Pro - Shaozhi On The Net
How To: MacBook Pro Late 2011 Memory Upgrade - 16GB (2 X 8GB) : 6 Steps - Instructables
Timetec Hynix IC 8GB Compatible for Apple DDR3L 1600MHz PC3L-12800 SODIMM Memory Upgrade for Early/Mid/Late 2011, Mid/Late 2012, Early/Late 2013, Late 2014, Mid 2015 MacBook Pro, iMac, Mac Mini (8GB) - Newegg.com
Early 2011 Macbook Pro Upgrades | MacRumors Forums
How to upgrade the RAM on your 13-inch MacBook Pro
16GB Kit (2 x 8GB) PC3-10600 RAM for Apple MacBook Pro Early 2011 - 13 Inch