Mathematics 57 Chemistry 51 Statistics 39 atmosphere 37 Engineering 34 Climatology 33 Physics 31 Finite element method 30 Genetics 28 Group theory 28 Chemical elements 27 Differential equations-- Analysis-- Mathematics 24 History 23 Economics 21 Trace elements 20 Dynamics 18 Ecology 18 Farm management 18 Nutrition 17 Psychology 16 Calculus 15 Biotechnology 14 Mercantile law--Law of contracts 14 Biochemistry 13 Functional analysis-- Mathematics 13 Mathematical analysis 13 Philosophy 13 Statics 13 farm management-economic aspects 13 Elements 12