References
- For a comprehensive review, seeDennemanJ. W.Jr.; “Low pressure sodium discharge lamps”; IEE Procedures, Vol. 128, Part A, No. 6, September 1981, pp. 397–414.
- KöstlinH., “Application of thin semiconductor and metal films in energy technology”, Festkörperprobleme (Solid State Physics) XXII (1982) pp. 229–254.
- U.S. Patent #4,401,693, G. Frank; H. Köstlin; L. M. Sprengers; and R. J. Campbell; “Method of Manufacturing a Heat-Reflecting Filter;” Issued August 30, 1983.