"...That said, I tell you that we are having some superb autumn days and that I am taking advantage of them. I have some studies, among others a mulberry tree all yellow on stony ground, outlined against the blue of the sky, in which study I hope you will see that I am on Monticelli's track." Letter from Vincent van Gogh to Theo van Gogh; Saint-Rémy, 5 October 1889. (http://www.tfsimon.com/auvers-sur-oise.html)