8Singh O P, Khan T M A,Rahman M S. Changes in the frequency of tropical cyclones over the north Indian ocean[J]. Meteorology and Atmospheric physics.2000,75:11-20.
9Lander M A,Guard C E A look at global tropical cyclone activity during 1995:contrasting high atlantics activity with low activity in other basins[J], monthly weather review. 1998,126:1163-1173.