Kumar, S. V., and P. S. Raghavaiah. 2000. “New Concepts in Bio-Diversity Conservation, Publicity and Extension - Environmental Education Centre At Tirumala (Tirupati) - Use of Spiritual Theme - a Case Study”. Indian Forester 126 (1):9-15. https://doi.org/10.36808/if/2000/v126i1/3125.