RT Journal Article SR Electronic T1 Defining service catchment areas in low-resource settings JF BMJ Global Health JO BMJ Global Health FD BMJ Publishing Group Ltd SP e006381 DO 10.1136/bmjgh-2021-006381 VO 6 IS 7 A1 Peter M Macharia A1 Nicolas Ray A1 Emanuele Giorgi A1 Emelda A Okiro A1 Robert W Snow YR 2021 UL http://gh.bmj.com/content/6/7/e006381.abstract AB