APA

Gibson R., Barlow A. & Watt f. (2003). Fun With Numbers. London: Usborne.

Chicago

Gibson Ray, Barlow Amanda and Watt fiona. 2003. Fun With Numbers. London: Usborne.

Harvard

Gibson R., Barlow A. and Watt f. (2003). Fun With Numbers. London: Usborne.

MLA

Gibson Ray, Barlow Amanda and Watt fiona. Fun With Numbers. London: Usborne. 2003.