Ecology 1 372 Dissertations, Academic (Ph.D) 1 047 Human ecology 355 Criticism and interpretation 187 Ecology-- Biodiversity-- Conservation 174 Ecology-- Biodiversity-- Conservation-- Ecosystems 135 Thesis (Ph.D)-Hindi literature 135 Agronomy 126 Microbiology 122 Environment 119 Marine ecology-- Ocean ecology-- Sea ecology 117 Thesis (Ph.D)-Commerce 111 Kerala 110 Thesis (Ph.D)-Malayalam literature 109 Biology 108 Thesis (Ph.D)-English literature 103 Plant Biotechnology 102 Agriculture 99 Forest ecology 94 Pathology 93 Microbial ecology 88 Biodiversity 87 Education 86 Sustainable development 85 Thesis (Ph.D)-Economics 84 ecology 84 Plant ecology 82 Thesis (Ph.D)-Botany 82 History 80 Dissertations, Academic(Ph.D) 78