Davis, B. Spatial reasoning in the early years: Principles, assertions, and speculations (1a ed.).
Chicago-referens (17:e uppl.)Davis, Brent. Spatial Reasoning in the Early Years: Principles, Assertions, and Speculations. 1a ed.
MLA-referens (8:e uppl.)Davis, Brent. Spatial Reasoning in the Early Years: Principles, Assertions, and Speculations. 1a ed.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.