Louwman, Marieke WJ; van Dusseldorp, Marijke; van de Vijver, Fons JR; Thomas, Chris MG; Schneede, Jørn; Ueland, Per M; Refsum, Helga; van Staveren, Wija A (). „Signs of impaired cognitive function in adolescents with marginal cobalamin status”. The American Journal of Clinical Nutrition. Oxford University Press (OUP). 72 (3): 762–769. doi:10.1093/ajcn/72.3.762. ISSN0002-9165.
Louwman, Marieke WJ; van Dusseldorp, Marijke; van de Vijver, Fons JR; Thomas, Chris MG; Schneede, Jørn; Ueland, Per M; Refsum, Helga; van Staveren, Wija A (). „Signs of impaired cognitive function in adolescents with marginal cobalamin status”. The American Journal of Clinical Nutrition. Oxford University Press (OUP). 72 (3): 762–769. doi:10.1093/ajcn/72.3.762. ISSN0002-9165.