Solid state physics; Properties of matter 268 Solid state physics 139 Solid state chemistry 87 History 86 Physics 65 Online social networks 59 Online journalism 56 Dissertations, Academic (Ph.D) 52 Social media 40 Journalism 39 Philosophy 37 Research 35 Agronomy 27 Mass media 26 Internet 24 Agriculture 23 Chemistry 22 Internet marketing 22 Management 22 Thesis (Ph.D)-Education 22 Economics 21 Biotechnology 20 Psychology 20 Social sciences 20 Soil science 20 Digital media 19 Literature 19 Social aspects 19 Citizen journalism 18 Ecology 17