1. Cereal situation and the yield gap: country by country summary;Anon.,1979
2. Evaluating N fertilizer sources and timing for winter wheat;Christensen;Agron. J.,1982
3. Effects of post-planting applications of nitrogenous fertilizers on grain yield, grain protein content and mottling of wheat;Cooper;Queensl. J. Agric. Anim. Sci.,1974
4. Systems of management of cereals for improved yield and quality;Dobben,1966