Amazon.com: OWC 1.0TB Aura Pro X2 SSD Compatible with MacBook Air (Mid 2013-2017), and MacBook Pro (Retina, Late 2013 - Mid 2015), and Mac Mini (Late 2014) : Electronics
Apple MacBook Pro A1502 Mid-2014 13" Retina i7 @ 3.0GHz 16GB RAM 500GB SSD *READ | eBay
PCIe SSD Hard Drive 512GB For MacBook Air, Pro & Mac Pro
PCIe SSD – Apple MacBook Pro 13″ / 15″ Retina (Late 2013, Mid 2014)
Amazon.com: Mid-2014 Apple MacBook Pro with 2.5GHz Intel Core i7 (15-inch, 16GB RAM, 512GB SSD Storage) (Renewed) : Electronics
Amazon.com: OWC 240GB Aura Pro X2 SSD Compatible with MacBook Air (Mid 2013-2017), MacBook Pro (Retina, Late 2013 - Mid 2015), and Mac Mini (Late 2014) : Electronics
MacBook Pro 13" Retina 128GB SATA SSD Solid State Drive, Late 2013 / Mid 2014 - 661-8135
MacBook Pro 13" and 15" Retina (Late 2013-Mid 2014) SSD
Amazon.com: GODSHARK M.2 NVME SSD Convert Adapter for MacBook Air Pro Retina Mid 2013 2014 2015 2016 2017, NVME/AHCI SSD Upgraded Kit for A1465 A1466 A1398 A1502 : Electronics
Apple MacBook Pro with Retina Display (15-inch, 2014) review: Still the best higher-res laptop, but the competition is catching up - CNET
SSD Upgrades for 2013, 2014, and 2015 MacBook Pro
Late 2013-2014 Macbook Pro Retina SSD Upgrade Notes - YouTube