Schäfer, R. (2007). Climate, Water Supply, Energy and Food: Challenges for the future. Topos.
Chicago-Zitierstil (17. Ausg.)Schäfer, Robert. "Climate, Water Supply, Energy and Food: Challenges for the Future." Topos 2007.
MLA-Zitierstil (8. Ausg.)Schäfer, Robert. "Climate, Water Supply, Energy and Food: Challenges for the Future." Topos, 2007.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.