1Dr. Herman Nilsson-Ehle MD,Sten Landahl MD, PhD,G?ran Lindstedt MD, PhD,Lisbeth Netterblad MLSO,Reinhold Stockbruegger MD, PhD,Jan Westin MD, PhD,Christer ?hren MD, PhD. Low serum cobalamin levels in a population study of 70- and 75-year-old subjects[J] 1989,Digestive Diseases and Sciences(5):716~723