APA

christie a., . (1991). the clocks. New York: harperpaperbacks.

Chicago

christie agatha, . 1991. the clocks. New York: harperpaperbacks.

Harvard

christie a., . (1991). the clocks. New York: harperpaperbacks.

MLA

christie agatha, . the clocks. New York: harperpaperbacks. 1991.