(1997). On solid ground: Science, technology, and intergrated land management. Canada: UNCTD.
Dyfyniad Arddull ChicagoOn Solid Ground: Science, Technology, and Intergrated Land Management. Canada: UNCTD, 1997.
Dyfyniad MLAOn Solid Ground: Science, Technology, and Intergrated Land Management. Canada: UNCTD, 1997.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.