6Crump JA, Mintz ED. Global trends in typhoid and paratyphoid fever. Clinical Infectious Diseases,2010,50(2) :241-246.
7Karsentg E, Leventhal A. Health geographic information systems (HGIS)-a tool for health planning and epidemiology. Harefuah, 2002, 141 (12) : 1070-1307,1089.
8Richards T, Comer C, Rushton G, et al. Geographic information sys- tems and public health:mapping the future. Public Health Rep, 1999, 114(4) :359-373.
9Moreira R, Nico L, Tomita N. The relation between space and collective oral health:For a georeferenced epidemiology. Cien Saude Colet,2007, 12( 1 ) :275-284.
10Antunes J, Frazao P, Narvai P. Spatial analysis to identify differentials in dental needs by area-based measures. Community Dent Oral Epidemiol,2002,30 ( 2 ) : 133-142.
