MATERIALS AND MOLDING METHODS 4-23 



REFERENCES 



(25) Guiffria, R-. Microscopic Study of Expandable Poly- 

 styrene Bead, Prepuff and Foam. Modern Plastics, 

 June 1959 



(26) Brenner, W., Foam Plastics - Manual No. 127, 

 Materials in Design Engineering, Reinhold Publishing 

 Co. , New York, 1959 



(27) Humke, R. K. , Selection Guide for Sandwich Panel 

 Cores - Product Engineering, January 1958 and 

 April 1958 



(2 8) Marshall, A. , Designers' Guide to Honeycomb - 



Sandwich Structures, Machine Design, May 15, 1959 



