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Ege, Markus J; Mayer, Melanie; Normand, Anne-Cécile; Genuneit, Jon; Cookson, William O C M; Braun-Fahrländer, Charlotte; Heederik, Dick; Piarroux, Renaud; von Mutius, Erika (2011). Exposure to environmental microorganisms and childhood asthma. New England journal of medicine NEJM, 364(8), pp. 701-9. Waltham, Mass.: Massachusetts Medical Society MMS 10.1056/NEJMoa1007302
