Ford, D. C., & Williams, P. W. (1989). Karst geomorphology and hydrology. Chapman & Hall.
Lua i Stíl Chicago (17ú heag.)Ford, D. C., agus P. W. Williams. Karst Geomorphology and Hydrology. London: Chapman & Hall, 1989.
Lua MLA (9ú heag.)Ford, D. C., agus P. W. Williams. Karst Geomorphology and Hydrology. Chapman & Hall, 1989.
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