Valdivia C, Poulos C. Factors affecting farm operators' interest in incorporating riparian buffers and forest farming practices in northeast and southeast Missouri. Agroforest Syst. 2009 Jan 1;75(1):61-71.
Urrutia I, Aguirre U, Sunyer J, Plana E, Muniozguren N, Martinez-Moratalla J. Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II). Arch. Bronconeumol. 2007 Aug;43(8):425-30.