In An Autobiography, Christie states, "I was still writing in the Sherlock Holmes tradition – eccentric detective, stooge assistant, with a Lestrade-type Scotland Yard detective, Inspector Japp".
Oma autobiograafias tunnistab Christie: "Ma kirjutasin endiselt Sherlock Holmesi stiilis - ektsentriline detektiiv, rumalavõitu abiline ning Lestrade'i-tüüpi Scotland Yardi detektiiv, inspektor Japp."