Definition: Intramural and extramural R&D
Expenditure on R&D may be made within the statistical unit (intramural) or outside it (extramural) R&D expenditure data should be compiled on the basis of performers' reports of intramural expenditures. The collection of extramural expenditures is, however, also desirable as a supplementary source.
Organisation for Economic Co-operation and Development (OECD), "Main Definitions and Conventions for the Measurement of Research and Experimental Development (R&D). A Summary of the Frascati Manual 1993", OECD, Paris, 1994, p.20