United Nations Economic and Social Council. Statistical Commission. (1974). Draft standard international trade classification (STIC), rev.2. United Nations Economic and Social Council.
Cita Chicago (17th ed.)United Nations Economic and Social Council. Statistical Commission. Draft Standard International Trade Classification (STIC), Rev.2. Geneva: United Nations Economic and Social Council, 1974.
Cita MLA (9th ed.)United Nations Economic and Social Council. Statistical Commission. Draft Standard International Trade Classification (STIC), Rev.2. United Nations Economic and Social Council, 1974.
Atenció: Aquestes cites poden no estar 100% correctes.