United States. Department of State & United States. Department of State. Office of the Procurement Executive. (1990). U.S. Department of State procurement system certification handbook. U.S. Dept. of State.
Chicago Style (17th ed.) CitationUnited States. Department of State and United States. Department of State. Office of the Procurement Executive. U.S. Department of State Procurement System Certification Handbook. [Washington, D.C.]: U.S. Dept. of State, 1990.
MLA (9th ed.) CitationUnited States. Department of State and United States. Department of State. Office of the Procurement Executive. U.S. Department of State Procurement System Certification Handbook. U.S. Dept. of State, 1990.
Warning: These citations may not always be 100% accurate.