1. Abraham, H. (1960). Asphalt and allied substances, 6th edn. Princeton, NY: Van Nostrand.
2. Akpoveta, O. V., & Osakwe, S. A. (2014). Determination of heavy metal contents in refined petroleum products. IOSR Journal of Applied Chemistry,7(6), 1–2.
3. Asphalt Institute and Eurobitume. (2011). The bitumen industry—a global perspective: Production, chemistry, use, specification, and occupational exposure, 2nd edn IS-230. Lexington, KY: Asphalt Institute.
4. Birgisdottir, H., Gamst, J., & Christensen, T. H. (2007). Leaching of PAHs from hot mix asphalt pavements. Environmental Engineering Science,24(10), 1409–1422.
5. Canadian Council of Ministers of the Environment. (2018). Canadian Environmental Quality Guidelines.
https://www.ccme.ca/en/resources/canadian_environmental_quality_guidelines/
. Accessed November 2018.