1. T.W. Goodwin, “Carotenoids: Their Comparative Biochemistry,” Chemical Publishing Co., New York, 1954, Chapter X.
2. H. H. Jaffe and M. Orchin, “Theory and Application of Ultraviolet Spectroscopy,” John Wiley and Sons, New York, 1961, pp. 228–235.
3. D. W. Sears and S. Beychok, “Physical Principles and Techniques of Protein Chemistry,” Part C ed. by J. Leach, Academic Press, New York, 1973, pp. 495–501.