Street-level governments : assessing decentralization and urban services / Robert K. Yin.- Lexington : Lexington Books, 1975.- XVIII, 276 ; 23 cm.

Case study research : design and methods / Robert K. Yin.- Thousand Oaks [etc.] : Sage, 2003.- XVI, 179 p. ; 22 cm..- Applied social research methods series 5