Relationship Between Sea Surface Temperature, Southern Oscillation, Position of the 500 mb Ridge along 75°E in April and the Indian Monsoon Rainfall Kumar, R; Sastry, J.S. Journal of the Meteorological Society of Japan 68(6): 741-745 1990 0026-1165 10.2151/jmsj1965.68.6_741 https://eurekamag.com/research/062/125/062125605.php