Harrar, J. Principles for progress in world agriculture. [New York]: 1966 16 p.
Harrar, J. Principles for progress in world agriculture. [New York]: 1966 16 p.
Harrar, J. (1966) Principles for progress in world agriculture, [New York]: 16 p.
Harrar, J. (1966). Principles for progress in world agriculture. Presented at the 33rd annual meeting of the National Agricultural Chemicals Association, White Sulphur Springs, West Virginia. [New York]: 16 p.
Harrar J. Principles for progress in world agriculture: Presented at the 33rd annual meeting of the National Agricultural Chemicals Association, White Sulphur Springs, West Virginia. [New York]: 1966. p. 16 p.