1. 1. Doherty D.J., FIurd R., Lester G.R., Chemistry and Industry, 20, 1962, 1340
2. Urethane Rigid Foams: Factors Affecting their Behaviour as Thermal Insulants
3. 3. Harding R.H., James B.F., Modern Plastics, 39(7), 1962, 133
4. 4. Knox R.E., paper, presented to the Plastics Foam Insulation Conference of SPI, April (1962)
5. 5. Stevenson M.E.Jr, Mark M., ASHREA Journal, 3 (2), Feb. (1961)