Grego, P. (2009). The great big book of space. Sandy Creek.
Cita Chicago Style (17a ed.)Grego, Peter. The Great Big Book of Space. New York: Sandy Creek, 2009.
Cita MLA (8a ed.)Grego, Peter. The Great Big Book of Space. Sandy Creek, 2009.
Precaución: Estas citas no son 100% exactas.