NEW Battery For Apple MacBook Pro Retina 13" A1425 2012 2013 Battery A1437 | eBay
NewerTech NuPower Battery for 2009-2012 13" NWTBAP13MBU74V B&H
iFixit posts repair guide for Retina MacBook Pro, estimates battery replacement at $500 - 9to5Mac
Battery Life - 13-inch Retina MacBook Pro Review (Late 2012)
Apple MacBook Pro 13" Retina A1425 A1437 battery - battery.com.sg
Apple Has Fully Restored Inventory of Mid 2012 and Early 2013 MacBook Pro Batteries - MacRumors
New A1437 74WH Laptop Battery Compatible with MacBook Pro 13 inch A1425 ( Retina Late 2012,Early 2013) Fits MD101 MD102 MD212 MD213 ME662 [6600mAh 11.21V]