NewerTech® : Batteries : NuPower® Battery for MacBook Pro 15" Unibody Early & Late 2011, Mid-2012 Models
Amazon.com: A1417 Battery Only for (Mid 2012 & Early 2013) A1398 MacBook Pro - Replacement Battery for A1398 MacBook Pro 15-inch Retina (Mid 2012, Early 2013 Version) - EMC 2512 or 2673 [11.26V/99Wh] : Electronics
Apple MacBook Pro (15 inch) review: Apple MacBook Pro (15 inch, Summer 2012) - CNET
NewerTech® : Batteries : NuPower® Battery for MacBook Pro 15" Retina mid 2012 to early 2013 Models
Replacing Battery for Macbook Pro 15" Late 2013 (iFixit Kit) A1494 - YouTube
MacBook Pro 15" Retina Top Case w/ Battery (Mid 2012 - Early 2013) - 661-6532
Temark New A1382 Battery for MacBook Pro 15 inch A1286 (only for Early 2011, Late 2011, Mid 2012), fit MC721LL/A MC723LL/A 661-5844 020-7134-A
Amazon.com: A1417 Battery Only for (Mid 2012 & Early 2013) A1398 MacBook Pro - Replacement Battery for A1398 MacBook Pro 15-inch Retina (Mid 2012, Early 2013 Version) - EMC 2512 or 2673 [11.26V/99Wh] : Electronics