1. The I.E.S. Code, Recommendations for good interior lighting,1961
2. The Offices, Shops and Railway Premises Act,1963-1963
3. The permanent supplementary artificial lighting of interiors;Hopkinson;Trans. Illum. Engng. Soc.,1959
4. Lighting: the use of permanent supplementary artificial lighting;Hopkinson;Archit. J.,1959
5. The permanent supplementary artificial lighting of interiors (PSALI),1960