Vorster, O. 2005. “The Use of Parallel Plate Rheology to Determine the Intrinsic Viscosity of Polyethylene Terephthalate”. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt; 24 (4), 134-38. https://doi.org/10.4102/satnt.v24i4.182.