The Cubic kilometre reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Cubic kilometre

Sponsorship the way you would do it
A cubic kilometre (symbol km³) is an SI derived unit of volume. It is the volume of a cube of side length 1 kilometre (1000 metre).

See 1 E9 m³ for a comparison with other volumes.

cubic metre << cubic kilometre << cubic megametre