1. How to cook the energy accounts;Kenward;New Scientist,1975
2. Environment, pollution, energy and materials;Kreijger;Matériaux et Constructions,1973
3. Beton in onze planetaire huishouding;Kreijger;Cement,1974
4. Building materials versus energy;Kreijger,1975
5. Energy conservation: Ways and means,1974