World Intellectual Property Organization. (2006). International patent classification: Core level (8. edition.). [Geneva, Switzerland]: WIPO.
Chicago Style CitationWorld Intellectual Property Organization. International Patent Classification: Core Level. 8. edition. [Geneva, Switzerland]: WIPO, 2006.
MLA CitationWorld Intellectual Property Organization. International Patent Classification: Core Level. 8. edition. [Geneva, Switzerland]: WIPO, 2006.
Warning: These citations may not always be 100% accurate.