The phrase "documents proving that" is a valid and usable expression in written English.
You can use it to refer to documents that are evidence of the validity of a particular claim or assertion. For example, "The defense attorney presented documents proving that the defendant was not at the scene of the crime."
Mr. Hemstreet wrote back that he would convey the mantel to Columbia "upon your covenant just received that the relic 'will be appropriately placed and sedulously cared for.'" He handed it over, along with a sheaf of "documents proving that Edgar Allan Poe had written in the room where the mantel stood his poem 'The Raven.'" Then began the search for an appropriate place.
But the Tories claim to have documents proving that his parliamentary apology was misleading as well.
Its officials check house-to-house demanding to see documents proving that the occupant is the owner.
The Easy Going Coffee Shop has a computer console at the door where identification documents proving that customers are 18 or older are scanned and recorded.
Whatever the case, in the summer of 2010 Ambrus lured Szegedi to his farm and told him that he had documents proving that Szegedi had Jewish origins.
He was part of a team of international historians that found documents proving that Deutsche Bank had financed the building of Auschwitz.
That was followed swiftly by the Powers report, a 218-page document proving that, instead of being the company of the 21st century, Enron was a sham corporation run by a bunch of greedy yahoos.
A federal judge later curbed the law's implementation, but Texas still requires voters to either present one of several forms of photo ID or a document proving that obtaining one imposed an unnecessary burden.
The document proved that Li had been born Yamaguchi Yoshiko, the daughter of Japanese parents in Manchuria, a colony of Japan before the second world war.
It said the documents prove that Georges Wildenstein exchanged letters, did business and had meetings with Haberstock.
