Name a written source that is suggested to have inspired van Gogh in this work ?
Among the evidence that confirmed the painting 's authenticity was a letter written by Vincent van Gogh to his brother Theo on 5 July 1888 , describing a landscape that he had painted the previous day : On 9 September 2013 , the Van Gogh Museum announced in a public unveiling of the painting , that the work had been confirmed as a painting by van Gogh .