MacBook Pro: How to remove or install memory - Apple Support
MacBook Pro with Retina display review (13-inch, 2013) | Engadget
MacBook Pro 13" Retina Display Late 2013 Logic Board Replacement - iFixit Repair Guide
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
How to upgrade Apple MacBook Pro RAM - YouTube
MacBook Pro 13" Retina Display Early 2015 Teardown - iFixit