MacBook Pro: How to remove or install memory - Apple Support
Review Apple MacBook Pro 15 Retina 2.3 GHz Mid 2012 - NotebookCheck.net Reviews
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com
4GB Ram Memory (PC3L-12800, DDR3 1600MHz) for Apple MacBook Pro 15 inch A1286, 13 inch A1278 . iMac 21.5 inch A1418 , 27 inch A1419 , Mac Mini A1347 ( Mid 2012 - Mid 2015) - MacWave
MacBook Pro: How to remove or install memory - Apple Support (MY)
Is upgrading the mid-2012 MacBook Pro Worth It? - Learn Robotics
MacBook Pro: How to remove or install memory – Apple Support (UK)
Retina Display MacBook Pro FAQ (A1398, A1425, A1502): EveryMac.com
MacBook Pro with Retina display review (15-inch) - The Verge
MacBook Pro 15" Retina Display Mid 2012 Teardown - iFixit