The earth : its shape, internal structure and composition / prepared by the Science Foundation Course Team. - Bletchley, Bucks : Open University Press, 1971. - 45 p. : ill. (some col.), maps ; 30 cm. - Science foundation course ; unit 22 . - Science foundation course ; unit 22-23. .

"S100 22 and 23"--Cover. Subtitle on cover: The earth's magnetic field.

0335020348


Earth.
Geomagnetism.


Earth--Internal structure.