Restored Apple A1398 MC975LL/A 15.4" MacBook Pro, Mac OS X 10.11 El Capitan, Intel Core i7-3615QM Processor, 16GB RAM, 256GB Solid State Drive (Refurbished) - Walmart.com
MacBook Pro 15” Retina A1398: How to Upgrade SSD or Replace Faulty One - YouTube
Macbook Pro 15" Retina A1398 Take Apart (2012 Model) - YouTube
16GB 2X8GB RAM Memory for Apple MacBook Pro A1398 Black Diamond Memory Module DDR3 SO-DIMM 204pin PC3-10600 1333MHz Upgrade - Walmart.com
Restored Apple A1398 MC975LL/A 15.4" MacBook Pro, Mac OS X 10.11 El Capitan, Intel Core i7-3615QM Processor, 16GB RAM, 256GB Solid State Drive (Refurbished) - Walmart.com
Logic Board for 2015 Apple MacBook Pro Retina i7 16GB, A1398
15" 15 Inch Retina MacBook Pro A1398 Mid 2015 Complete Disassembly (Almost) SSD Upgrade - YouTube
Can I upgrade the RAM of the MacBook Pro 13' Retina from 8gb to 16gb after/during purchase? - Quora