Butt, Graham. MasterClass in Geography Education: Transforming Teaching and Learning. MasterClass series. London: Bloomsbury Academic, 2015. Print.
Hart, Kathleen. ‘Chapter 7, Ratio and Proportion’. Children’s Understanding of Mathematics, 11-16. London: John Murray, 1981. 88–97. Web. <https://contentstore.cla.co.uk/secure/link?id=8c863559-bf1d-e611-80bd-0cc47a6bddeb>.
Jones, Mark. The Handbook of Secondary Geography. Sheffield: Geographical Association, 2017. Print.
Lambert, David, and Mark Jones. Debates in Geography Education. Debates in subject teaching series. London: Routledge, 2013. Print.
