J. S. Alm et al. “Atopy in Children of Families with an Anthroposophic Lifestyle” Lancet 353, № 9163 (1999); T. Alfvén et al. “Allergic Diseases and Atopic Sensitization in Children Related to Farming and Anthroposophic Lifestyle — the Parsifal Study”. Allergy 61, № 4 (2006).