Other national R-D expenditure by field of science and by source of funds includes statistics on research and development ( R&D) expenditure performed in the higher education and private non-profit sectors by field of science (natural sciences, engineering, medical sciences, agricultural sciences, social sciences, and humanities) and source of funds (direct government, public general university funds, higher education, private non-profit, business enterprise, and funds from abroad). Data are presented from 1981 onwards. Data are expressed in units for expenditure such as current prices, constant prices and in terms million of national currency.