What has the author A P Benthall written?

It seems you might be mistaking the name. There's no widely known author named "A. P. Benthall."

It's possible you're thinking of:

* A.P. Herbert: A British humorist, satirist, and playwright known for his books like "The Water Gypsies" and "Holy Deadlock."

* A.P. Watt: A literary agency founded by Alfred Percival Watt, who represented prominent authors like Arthur Conan Doyle and H.G. Wells.

If you can provide more context, like a book title or the type of writing, I might be able to help you find the correct author.