A. N. CHOPRA, . H. S. AHUJA, M. M. SETH, P. BHATTACHARYA, and K. CHATTERJEE, “INTERCALIBRATION OF DOBSON OZONE SPECTROPHOTOMETERS IN THE INDIAN NETWORK (1978-80)”, MAUSAM, vol. 32, no. 4, pp. 440–441, Oct. 1981.