1. Maturation of sunflower;Anderson;Aust. J. Exp. Agric. Anim. Husb.,1975
2. Berglund, D.R., 2007. Sunflower production. North Dakota State University Ext. Serv. Bulletin A-1331 (EB-25 Revised). Available at http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/a1331intro.pdf (verified 24 Jan. 2013).
3. Concentrations of chlorogenic acid, oil, and fatty acids in developing sunflower seeds;Dorrell;Crop Sci.,1978
4. Seed Growth and Development. Seed Biology and the Yield of Grain Crops;Egli,1998
5. Franzen, D.W., 2010. North Dakota fertilizer recommendation table and equations. North Dakota State Univ. Ext. Serv. Bulletin SF-882 (Revised). Available at http://www.ndsu.edu/fileadmin/soils/pdfs/sf882.pdf (verified 24 Jan. 2013).