Apple MacBook Pro 13.3" Intel Core i5 4GB RAM 320GB Hard Drive (MC700LL/A) Early 2011 (Certified Refurbished) Silver A1278 - Best Buy
MacBook Pro A1278 SK Hynix 2GB SO-DIMM PC3L-12800S RAM Memory HMT425S6AFR6A-PB
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com
4GB RAM Memory (PC3-8500) for Apple MacBook 13 inch A1278 Late 2008, A1342 Late 2009, A1342 Mid 2010. Apple MacBook Pro 13 inch A1278 Mid 2009, A1278 Mid 2010, A1286 - Late 2008
Macbook Pro RAM Upgrade Kit 8GB 2 x 4GB 2011 2012 A1278 A1286 13 15" 10600s DDR3 836905536579 | eBay
2012 Macbook Pro 13" A1278 RAM Upgrade - YouTube
Apple MacBook Pro 5.5 Mid 2009 13.3" A1278, Core 2 Duo, 240GB SSD, 8GB RAM | eBay
MacBook Unibody Model A1278 RAM Replacement - iFixit Repair Guide