1. Christie WW. The analysis of evening primrose oil. Ind. Crops Prod. 1999;10:73-83.
2. Cheema MA, Malik MA, Hussain A, Shah SH, Basra, SMA. Effect of time and rate of nitrogen phosphorus application on the growth, seed and oil yield of canola (Brassica napus L.). J. Agron. Crop Sci. 2001;186:103-110.
3. Court WA, Hendel JG, Pocs R. Determination of the fatty acids and oil content of evening primrose (Oenothera biennis L.). Food Res. 1993;26:181-186.
4. Delacruz JP. Effect of evening primrose oil on platelet aggregation in rabbits fed, an atherogenic diet. Thromb. Res. 1977;78:141-149.
5. El-Hafid R, Blade, SF, Hoyano Y. Seeding and nitrogen fertilization effects on the performance of borage (Borago officinalis L.). Ind. Crops Prod. 2002;16:193-199.
6. Fieldsend AF. Evening primrose from garden flower to oilseed crop. The Horticulturist. 1996;5:2-5.
7. Fieldsend AF, Morison JIL. Climatic conditions during seed growth significantly influence oil content and quality in winter and spring evening primrose crops (Oenothera spp.). Ind. Crops Prod. 2000a;12: 137-147.
8. Fieldsend AF, Morison JIL. Contrasting growth and dry matter partitioning in winter and spring evening primrose crops (Oenothera spp). Field Crops Res. 2000b; 68:9-20.
9. Ghasemnezhad A, Honermeier B. Seed yield, oil content and fatty acid composition of Oenothera biennis L. affected by harvest date and harvest method. Ind. Crops Prod. 2007;25:274-281.
10. Ghasemnezhad A, Honermeier B. Yield, oil constituents and protein content of evening primrose (Oenothera biennis L.) seeds oil depending on harvest time, harvest method and nitrogen application. Ind. Crops Prod. 2008;28:17-23.
11. Growley JG, Fröhlich A. Factors affecting the composition and use of Camelina. Crop Research Center, Oak Park, Carlow 1998.
12. Hocking PJ. Effects of nitrogen supply on the growth, yield components, and distribution of nitrogen in linola. J. Plant Nutr. 1995;18:257-275.
13. Huang YS, Ziboh VA. γ-linolenic acid: recent advanced in biotechnology and clinical applications. Champaign Illinois: AOCS Press. 2000.
14. Johnson B, Forcella F, Gesch R. Cuphea seed yield and oil content response to harvest methods. The ASA – CSSA – SSSA International Annual Meeting. Salt Lake City, USA. 2005.
15. Johnson MM, Swan DD, Surette ME, Stegner J, Chilton T, Fonteh, AN, Chilton FH Dietary. supplementation with g-linolenic acid alters fatty acid content and eicosanoid production in healthy humans. J. Nutr. 1997;127:1435-1444.
16. Kris-Etherton PM, Taylor DS, Yu-Poth S, Huth P, Moriarty K, Fishell V, Hargrove RL. Polyunsaturated fatty acids in the food chain in the United States. Am. J. Clin. Nutr. 2000;71:179-188.
17. Levy A, Palvitch D, Ranen C. Increasing gamma linolenic acid in evening primrose grown under hot temperatures by breeding early cultivars. Acta Hort. 1993;330:219-225.
18. Murphy CL, Mc Kenny CB, Auld DL, Hopper NW. Field production of texas native evening primrose (Oenothera spp.) as a source of gamma linolenic acid. Acta Hort. 2004;629:283- 288.
19. Peschel W, Dieckmann W, Sonnenschein M, Plescher A. High antioxidant potential of pressing residues from evening primrose in comparison to other oilseed cakes and plant antioxidant. Ind. Crops Prod. 2007;25:44-54.
20. Reiner H, Marquard R. Investigations in cultivation abilities and seed quality of Oenothera biennis L. Food Sci. Technol. 1988;90:1-7.
21. Sekeroglu N, Özgüven M. Effects of different nitrogen doses and row spacing applications on yield and quality of Oenothera biennis L. grow in irrigated lowland and unirrigated dryland conditions. Turkish J. Agric. 2006;30:125-135.
22. Stumpf PK. Biosynthesis of fatty acids in higher plants. In: Röbbelen G, Downey RK, Ashri A, (Editors): Oil crops of the world, chapter 3, 38-62, McGraw- Hill Publishing Company. 1989.
23. Shewry PR, Napier JA, Sayanova O, Smith M, Cooke DT, Stoker G, Hill J, Stobart AK, Lapinkase P. Domestication, Production and Utilization of new crops 1997; p 76-87. International Center for Under-utilised Crops, Southampton.
24. Simpson MJA, Fieldsend AF. Evening primrose harvest methods and timing. Acta Hort. 1993;331: 121-128.
25. Simpson MJA. A description and code of development of evening primrose (Oenothera spp.). Annu. Appl. Biol. 1994;125:391-397.
26. Spain AV, Hodgen MJ. Changes in the composition of sugarcane harvest residues during decomposition as a surface mulch. Biol. Fertil. Soils. 1994;17:225-231.
27. Wilson RG, Smith JA. Influence of harvest –aid herbicide on Dry Bean (Phaseolus vulgaris) desiccation, seed yield and quality. Weed Technol. 2002;16:109- 1145.
28. Wolf RB, Kleiman L, England RE. New sources of g- linolenic acid. J. Am. Oil Chem. 1983;60:1858-60.
29. Yaniv Z, Ranen C, Levy A, Palevitch D. Effect of temperature on the fatty acid composition and yield of evening primrose seeds. J. Exp. Bot. 1989;40:609-613.
30. Zhao F, Evans EJ, Bilsborrow PE, Syres JK. Influence of sulphur and nitrogen on seed yield and quality of low glucosinilate oilseed rape (Brassica napus L.). J. Sci. Food Agric. 1993;63:29-37.