World Resources Institute. A Guide to world resources 2002-2004: Desicions for the earth balance, voice and power. S.n.
Cita Chicago Style (17a ed.)World Resources Institute. A Guide to World Resources 2002-2004: Desicions for the Earth Balance, Voice and Power. Washington, D.C.: S.n.
Cita MLA (9a ed.)World Resources Institute. A Guide to World Resources 2002-2004: Desicions for the Earth Balance, Voice and Power. S.n.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.