You can look for works of Robert Chambers of Institute of Development Studies. As example, see Rapid rural appraisal: Rationale and repertoire (http://onlinelibrary.wiley.com/doi/10.1002/pad.4230010202/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false) and Rural apprasial: rapid, relaxed and participatory (http://mobile.opendocs.ids.ac.uk/opendocs/handle/123456789/774#.U6VR4JSSy8p).