APA

Gibson R., Barlow A., . (2003). Number Activities. London: Usborne.

Chicago

Gibson Ray, Barlow Amanda, . 2003. Number Activities. London: Usborne.

Harvard

Gibson R., Barlow A., . (2003). Number Activities. London: Usborne.

MLA

Gibson Ray, Barlow Amanda, . Number Activities. London: Usborne. 2003.