APA (7th ed.) Citation

Christie, A. (1969). Hallowe'en party. Published for the Crime Club by Collins.

Chicago Style (17th ed.) Citation

Christie, Agatha. Hallowe'en Party. London: Published for the Crime Club by Collins, 1969.

MLA (8th ed.) Citation

Christie, Agatha. Hallowe'en Party. Published for the Crime Club by Collins, 1969.