United Nations. Economic Commission for Europe. (1983). Catalogue of building systems and components approved at the national level and aimed at international trade: Agreed format and example catalogue. United Nations.

United Nations. Economic Commission for Europe. Catalogue of Building Systems and Components Approved at the National Level and Aimed at International Trade: Agreed Format and Example Catalogue. New York: United Nations, 1983.

United Nations. Economic Commission for Europe. Catalogue of Building Systems and Components Approved at the National Level and Aimed at International Trade: Agreed Format and Example Catalogue. United Nations, 1983.