https://www.b12d.org/book/export/html/1502
http://www.discoveriesinmedicine.com/To-Z/Vitamin-B12.html
http://www.dailymail.co.uk/health/article-2191161/The-60p-injection-boost-flagging-energy.html
http://www.thejournal.co.uk/news/north-east-news/horden-gp-dr-joseph-chandy-4416898
http://shevlinsebastian.blogspot.in/2010/12/magic-vitamin.html
http://bebrainfit.com/vitamin-b12-deficiency-brain/
http://brainblogger.com/2014/07/30/vitamin-b12-deficiency-and-its-neurological-consequences/
http://kellybroganmd.com/article/b12-deficiency-brain-health/
http://well.blogs.nytimes.com/2013/12/10/acid-suppressing-drugs-linked-to-vitamin-b12-deficiency/
http://news.harvard.edu/gazette/1998/01.22/Red-BloodedDoct.html
http://www.wellbeingwithbrittany.com/tips-blog/2015/9/2/could-you-be-b12-deficient-the-dangers-of-b12-deficiency-what-you-need-to-know-now