History 105 Fiber optics 81 Philosophy 73 Economics 69 India 64 Biological diversity 56 Rivers 56 Dissertations, Academic (Ph.D) 54 Ecology 51 Economic growth and development-- Economic Planning 46 History and criticism 46 Social aspects 46 Biodiversity 45 Economic development 43 Education 42 Optical communications 41 Literature 38 Religion 38 Biotechnology 37 Women 35 Sociology 34 Management 32 Social conditions 32 Optical fiber communication 31 Social Sciences 31 Research 29 Feminism 28 Microbiology 28 Mass media 27 Optical fibers 27