Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys - Asher, M I; Montefort, S; Bjorksten, B (Lancet, 2006)
doi:10.1016/S0140-6736(06)69283-0