Richard Parsons. (2003). "National Curriculum Science: Earth, Sun and Moon: Unit 5e (National Curriculum Science)". Coordination Group Publications Ltd.
Chicago-čujuhus (17. p.)Richard Parsons. "National Curriculum Science: Earth, Sun and Moon: Unit 5e (National Curriculum Science)". Coordination Group Publications Ltd, 2003.
MLA-čujuhus (9. p.)Richard Parsons. "National Curriculum Science: Earth, Sun and Moon: Unit 5e (National Curriculum Science)". Coordination Group Publications Ltd, 2003.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.