APA
United Nations Industrial Development Organization Expert Group, Meeting on Technological Development in Lead and Sinc (1969 : London) & United Nations Industrial Development Organization Expert Group. (1970). Technological development in lead and zinc production and their significance to developing countires. New: York United Nations USA.
Chicago
United Nations Industrial Development Organization Expert Group, Meeting on Technological Development in Lead and Sinc (1969 : London) and United Nations Industrial Development Organization Expert Group. 1970. Technological development in lead and zinc production and their significance to developing countires. New: York United Nations USA.
Harvard
United Nations Industrial Development Organization Expert Group, Meeting on Technological Development in Lead and Sinc (1969 : London) and United Nations Industrial Development Organization Expert Group. (1970). Technological development in lead and zinc production and their significance to developing countires. New: York United Nations USA.
MLA
United Nations Industrial Development Organization Expert Group, Meeting on Technological Development in Lead and Sinc (1969 : London) and United Nations Industrial Development Organization Expert Group. Technological development in lead and zinc production and their significance to developing countires. New: York United Nations USA. 1970.