@book{55038,
	title = {Evaluation research methods},
	publisher = {SAGE,},
	year = {2005},
	series = {Sage benchmarks in social research methods},
	address = {London :Thousand Oaks, Calif. :},
	note = {v.1. Foundations issues in evaluation , v.2. Evaluation practice for engagement, v.3. Explanatory and economic models , v.4. Strengthening policies and programmes}
}