004050000a22001810004500003000900000005001700009264005900026020001800085020001500103100001800118245002600136050001200162300001000174041000800184650001700192500000600209040000800215PH-MaWHO20241108112716.0 aEdinburgh ; New York : bChurchill Livingstone,c1975. a9780443011061 a0443011060 aMorris, J. N. aUses of epidemiology. a3rd ed. a318p. aeng aEpidemiology a1 aNLM