Unwin, D. (1981). Introductory spatial analysis. Metheun.
Lua i Stíl Chicago (17ú heag.)Unwin, David. Introductory Spatial Analysis. London: Metheun, 1981.
Lua MLA (9ú heag.)Unwin, David. Introductory Spatial Analysis. Metheun, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.