Johan H. Langaard and Reidar Revold are authors known for their works on Edvard Munch, particularly focusing on his drawings and the Munch Museum. They co-authored books like "The Drawings of Edvard Munch" (1958) and "Edvard Munch: Masterpieces From the Artist's Collection in the Munch Museum in Oslo". Langaard also co-authored "The Munch Museum, The Building and its Collections