APA (7th ed.) Citation

Spain & United States. Department of State. (1999). Aviation: Safety : agreement between the United States of America and Spain signed at Washington, September 23, 1999. U.S. Dept. of State.

Chicago Style (17th ed.) Citation

Spain and United States. Department of State. Aviation: Safety : Agreement Between the United States of America and Spain Signed at Washington, September 23, 1999. [Washington, D.C.]: U.S. Dept. of State, 1999.

MLA (9th ed.) Citation

Spain and United States. Department of State. Aviation: Safety : Agreement Between the United States of America and Spain Signed at Washington, September 23, 1999. U.S. Dept. of State, 1999.