1. ?Plastics Extrusion Technology,? p. 125, Reinhold Pub. Corp., New York (1962).
2. ?Polymer Processing,? p. 111, John Wiley and Sons, New York (1962).
3. and in ?Processing of Thermoplastic Materials,? (ed.), p. 269, 299, Reinhold Pub. Corp., New York (1959).