James Fergusson, Tree and Serpent Worship: or, Illustrations of Mythology and Art in India in the first and fourth centuries after Christ. From the Sculptures of the Buddhist topes at Sanchi and Amravati. Prepared under the Authority of the Secretary of State for India in council. Second edition. Revised, corrected, and in great part re-written (London: India Museum, W.H. Allen & Co., publishers to the India Office, 1873), Plate XIII.