Jagadesan, S., & Subramanian, M. V. (2016). Study on Sunspots, Ozone and earth atmosphere variation at Pudukkottai, Tamilnadu (latitude: 10 0 23’ and longitude 78 0 52’). International Journal of Science and Engineering Invention, 2(08), 205 to 212. https://doi.org/10.23958/ijsei/vol02-i07/05