J. Butterworth,
«A brief review of service delivery concepts: a literature review»,
Triple-S Literature Reviews. IRC, The Hague, The Netherlands, p. 18 p.; 2 fig.; 4 tab.; 1 box, 2011.
T. Chaka, Yrgu, L., Abeba, Z., y Butterworth, J.,
«Ethiopia : lessons for rural water supply : assessing progress towards sustainable service delivery»,
Triple-S Country Studies. IRC, The Hague, The Netherlands, p. 44 p.; 3 tab.; 10 boxes, 2011.