RT Journal Article SR Electronic T1 An Evaluation of a Dual-Isotope Method for the Measurement of Vitamin B12 Absorption JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 135 OP 141 VO 14 IS 3 A1 Briedis, Dalius A1 McIntyre, Patricia A. A1 Judisch, Janifer A1 Wagner, Henry N. YR 1973 UL http://jnm.snmjournals.org/content/14/3/135.abstract AB