Cawthorne, Nigel (2014). A brief guide to Agatha Christie. London: Little, Brown Book Group. ISBN9781472110572. OCLC878861225.
Maida, Patricia D; Spornick, Nicholas B. (1982). Murder she wrote : a study of Agatha Christie's detective fiction. Bowling Green, Ohio: Bowling Green State University Popular Press. ISBN0879722150. OCLC9167004.
Tromans, Nicholas (2011). 'Hope' : the life and times of a Victorian icon. Watts Gallery (Compton, Surrey). Compton: Watts Gallery. ISBN9780956102270. OCLC747085416.
Kabatchnik, Amnon (2011). Blood on the stage, 1950-1975 : milestone plays of crime, mystery, and detection. Lanham: Scarecrow Press. ISBN9780810877849. OCLC715421383.