APA

Ford D., Williams P., . (1989). Karst geomorphology and hydrology. London: Unwin hyman.

Chicago

Ford D.C, Williams P.W, . 1989. Karst geomorphology and hydrology. London: Unwin hyman.

Harvard

Ford D., Williams P., . (1989). Karst geomorphology and hydrology. London: Unwin hyman.

MLA

Ford D.C, Williams P.W, . Karst geomorphology and hydrology. London: Unwin hyman. 1989.