APA (7th ed.) Citation

Harrison, V. L. (1976). Do sunspot cycles affect crop yields? U.S. Dept. of Agriculture, Economic Research Service.

Chicago Style (17th ed.) Citation

Harrison, Virden L. Do Sunspot Cycles Affect Crop Yields? [Washington]: U.S. Dept. of Agriculture, Economic Research Service, 1976.

MLA (9th ed.) Citation

Harrison, Virden L. Do Sunspot Cycles Affect Crop Yields? U.S. Dept. of Agriculture, Economic Research Service, 1976.