1. Abels J.: Intrinsic factor van Castle en resorptie van vitamin B12. Thesis. Univ. Groningen 1959.
2. Adams J. F.: Considerations governing the maintenance treatment of pernicious anaemia. In Heinrich: Vitamin B12 und Intrinsic-Factor. S. 628, Symposion 1961; F. Enke Verlag Stuttgart 1962
3. Allcock E.: Gastroenterol.40, 81 (1961).
4. Alsted G.: Lancet I, 76 (1937).
5. Arbo J., J. Mohr: Acta genet. et stat. med.8, 105 (1958).