Books Read in May

Howard Owen: Littlejohn
John Banville: Shroud
Boris Akunin: The Winter Queen
Ruth Rendell: Road Rage
Geraldine Brooks: Year of Wonders
Jane Gardam: Bilgewater
Ian Rankin: Set in Darkness
Jennifer Lauck: Blackbird
P.D. James: Shroud for a Nightingale
Agatha Christie: Evil Under the Sun

In one month, how did I manage to read two books with shroud in the title?