MacBook Pro 13" and 15" Retina (Late 2013-Mid 2014) SSD
MacBook Pro (Retina, 13-inch, Early 2015) Upgrade to NVMe M.2 SSD - YouTube
Upgrading 2013/2014 Macbook Pro SSD to M.2 NVMe | MacRumors Forums
Amazon.com: 256GB SSD Hard Drive for Apple MacBook Pro Air 11" 13" 15" A1502 A1398 A1465 A1466 (Late 2013-2015) / OSX Sierra/Mac Pro A1481 : Electronics
How to Upgrade MacBook Pro Retina SSD -mac&egg-
Crucial P2 2TB SSD on MacBook Pro 15" (Mid 2014) A1398 · Issue #3 · kvic-z/SsdPmEnabler · GitHub
MacBook Pro 13" and 15" Retina (Late 2013-Mid 2014) SSD