Clifford, N. J., Cope, M., Gillespie, T. W., & French, S. (2016). Key methods in geography (Third edition.). SAGE.
Lua i Stíl Chicago (17ú heag.)Clifford, N. J., Meghan Cope, Thomas W. Gillespie, agus Shaun French. Key Methods in Geography. Third edition. Los Angeles: SAGE, 2016.
Lua MLA (9ú heag.)Clifford, N. J., et al. Key Methods in Geography. Third edition. SAGE, 2016.
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