1. Anhydrous ammonia as a nitrogenous fertilizer;Andrews;Advance. Agron,1956
2. Anhydrous ammonia as a source of nitrogen;Andrews;Miss. Agr. Exp. Sta. Bull. 482,1951
3. Arkansas rice tests prove ammonia successful in Mississippi River Delta;Beacher;Agr. Ammonia News,1955
4. Variations in protein levels in Kansas sorghum grain;Miller;Agron. J,1964
5. Using fertilizer nitrogen effectively on grain crops;Olson;Neb. Agr. Exp. Sta. Bull. 479,1964