Great WWI stories that haven't been adapted for the screen?

The Middle Parts of Fortune by Frederic Manning. It was first published in 1929, with a censored version following a year later under the title Her Privates We. Manning was not credited as the author until 1943. The novel probably hasn't been adapted to film because it is somewhat more obscure than All Quiet on the Western Front (even though Manning's novel received praise from T.E. Lawrence and Ernest Hemingway, among others), and as such is harder to obtain. In addition, as the soldiers are British, the language is EXTREMELY crude (read: they throw around the c-word with some frequency), even by the standards of war stories (most of which don't venture past the f-word).