MacBook Pro 13" Retina Display Late 2012 SSD Replacement - iFixit Repair Guide
Amazon.com: Odyson - 128GB SSD Replacement for MacBook Pro 13" A1425 / 15" A1398 (Late 2012, Early 2013) : Electronics
Amazon.com: DATARAM SSD for 2012 Apple MacBook Air EMC 2558 & EMC 2559, SATA-III M.2 2280 Internal SSD (1TB) : Electronics
Replace your 2009-2012 MacBook Pro HD with an SSD
Used Adaptor to install mSATA in my late-2012 rMBP, it's working great! | MacRumors Forums
All Flash Storage & SDXC Reader - 13-inch Retina MacBook Pro Review (Late 2012)
Amazon.com: MCE Technologies 1TB Internal SSD Flash Upgrade for MacBook Pro Retina (Mid 2012 - Early 2013) - Includes USB 3.0 Enclosure for Original Drive & Install Kit! : Electronics