DFID Working Paper 38: Broadening the range of designs and methods for impact evaluations
Stern, E.; Stame, N.; Mayne, J.; Forss, K.; Davies, R.; Befani, B. (2012). DFID Working Paper 38. Broadening the range of designs and methods for impact evaluations. DFID, London, UK vi + 91 + 24 pp. http://r4d.dfid.gov.uk/Output/