Agatha Christie
English mystery and detective writer (1890–1976)
Dame Agatha Mary Clarissa Mallowan, Lady Mallowan, usually known by her first married name, Agatha Christie, was an English author known for her 66 detective novels and 14 short-story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She is widely regarded as one of the greatest writers, particularly in the mystery genre.
via WikipediaBooks (33)
Nemesis
Book 11

Sleeping Murder
Book 12

And Then There Were None
Appointment with Death

By the Pricking of My Thumbs
Cards on the Table
Cat Among the Pigeons

Crooked House
Curtain

Dead Man's Folly

Death Comes as the End

Death on the Nile
Elephants Can Remember
Endless Night
Hallowe'en Party
Hickory Dickory Death

Lord Edgware Dies

Murder in Mesopotamia
Murder in the Mews

Murder is Easy
Murder of Roger Ackroyd

Murder on the Links
Murder on the Orient Express

Ordeal by Innocence

Parker Pyne Investigates
Passenger to Frankfurt

Peril at End House

Postern of Fate
Sad Cypress

Sparkling Cyanide

They Came to Baghdad

Third Girl

Why Didn't they Ask Evans?