1. Baumann, G. F., Aulabaugh, S. J. and Steingiser, S. 1967.Resinography of Cellular Plastics, 68Philadelphia: ASTM. ASTM Special Technical Publication No. 414
2. Harding, R. H. 1967.Resinography of Cellular Plastics, 3Philadelphia: ASTM. (ASTM Special Technical Publication No. 414)
3. The unit of foaminess