Ibhadon, A. (1998). Fracture mechanics of polypropylene: effect of molecular characteristics, crystallisation conditions, and annealing on morphology and impact performance. Journal of Applied Polymer Science, 69(13), 2657 - 2661. https://doi.org/10.1002/%28SICI%291097-4628%2819980926%2969%3A13%3C2657%3A%3AAID-APP16%3E3.0.CO%3B2-R