Bayer AM, Danysh HE, Garvich M, Gonzalvez G, Checkley W, Alvarez M, Gilman RH. An unforgettable event: a qualitative study of the 1997-98 El Niño in northern Peru. Disasters. 2014 Apr;38(2):351-74. doi: 10.1111/disa.12046
Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA. Incidence of IBS in a cohort of people with asthma. Dig Dis Sci. 2007 Feb 28;52(2):329-35.