Maskey MK, Baral KP, Shah R, Shrestha BD, Lang J, Rothman KJ. Field test results of the motherhood method to measure maternal mortality. Ind Med Gaz. 2011 Jan 1;133(1):64-9.
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.