C. Metaxas, D. Mathis, C. Jeger, K. E. Hersberger, I. Arnet, and P. Walter, “Early biomarker response and patient preferences to oral and intramuscular vitamin B12 substitution in primary care: a randomised parallel-group trial”, Swiss Med Wkly, vol. 147, no. 1314, p. w14421, Apr. 2017.