Sixth World Petroleum Congress :
proceedings : Frankfurt/Main, June 19-26, 1963.
APA Citation
World Petroleum Congress (6th : 1963 : Frankfurt am Main, G. (1963). Sixth World Petroleum Congress: proceedings : Frankfurt/Main, June 19-26, 1963. Hamburg: Verein zur Förderung des 6. Welt-Erdöl-Kongress.
MLA Citation
World Petroleum Congress (6th : 1963 : Frankfurt am Main, Germany). Sixth World Petroleum Congress: Proceedings : Frankfurt/Main, June 19-26, 1963. Hamburg: Verein zur Förderung des 6. Welt-Erdöl-Kongress, 1963.
Warning: These citations may not always be complete (especially for serials).