Validation of a questionnaire to assess dietary habits among 5-13-year old school children of farmers and anthroposophic families. - Michels, Karin B.; Waser, Marco; Ary, Emmanuelle; Rosenlund, Helen; von Mutius, Erika; Riedler, Josef; Schram, Dieneke; Pershagen, Göran; Braun-Fahrländer, Charlotte (Journal of Nutritional & Environmental Medicine, 2008)