Here are entered works on the composite of physical, biological, and social sciences concerned with the conditions of the environment and their effects. Works on the interrelationships of organisms and their environment, including other organisms, are entered under Ecology. Works on the relationship of humans to the natural environment are entered under Human ecology. Works on the relationship of humans to their sociocultural environment are entered under Social ecology.
--subdivision Mathematics under topical headings for the mathematics applied in those fields, e.g. Investments--Mathematics; also phrase headings for types of mathematics; and headings beginning with the word Mathematical
Here are entered works on the science of measurement or of weights and measures. Works on the general process of measuring are entered under Measurement. Works on a system of standard units of measure are entered under Weights and measures.