1
Hart K. Chapter 7, Ratio and proportion. Children’s understanding of mathematics, 11-16. London: John Murray 1981:88–97.
2
Butt G. MasterClass in geography education: transforming teaching and learning. London: Bloomsbury Academic 2015.
3
Jones M. The handbook of secondary geography. Sheffield: Geographical Association 2017.
4
Lambert D, Jones M. Debates in geography education. London: Routledge 2013.