"http://dbpedia.org/resource/Concentration"^^ . "http://en.wikipedia.org/wiki/Concentration"^^ . . . "In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Furthermore, in chemistry, four types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. The term concentration can be applied to any kind of chemical mixture, but most frequently it refers to solutes in solutions." . . "Concentration"@en .