Letter from Needham to Bowles, June 1955.
Needham mentions that the thangka may come from Sera Monastery, Lhasa, Tibet.
Wesley E. Needham Papers. Tibet Mss 64. Box 1. General Collection, Beinecke Rare Book and Manuscript Library, Yale University.
Wesley Needham., “Letter from Needham to Bowles, June 1955. ,” Himalayan Collections @ Yale, accessed November 22, 2017, http://himalayancollections.commons.yale.edu/items/show/1621.