Clifford, N., French, S., & Valentine, G. (2010). Key methods in Geography (2a. ed.). Sage.
Lua i Stíl Chicago (17ú heag.)Clifford, Nicholas, Shaun French, agus Gill Valentine. Key Methods in Geography. 2a. ed. Los Angeles: Sage, 2010.
Lua MLA (9ú heag.)Clifford, Nicholas, et al. Key Methods in Geography. 2a. ed. Sage, 2010.
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