Sternennacht
He is the author of an acknowledged "catalogue raisonné" of Van Gogh's work, published in 1978, revised in 1989 and again in 1996. His catalogue numbers are preceded by a 'JH': thus JH1731 refers to the 1889 oil painting "The Starry Night" (previously catalogued by Jacob Baart de la Faille as F612).