Kawsakul, L., Yongmanitchai , W. and Chonudomkul, D. 2012. Optimization of Growth and Production of Docosahexaenoic Acid by Schizochytrium limacinum BR2.1.2 Using Plackett-Burman Design and Central Composite Design with Response Surface Methodology. Agriculture and Natural Resources. 46, 4 (Aug. 2012), 573–581.