Gardiner, B. (1990). Energy demands. London: Gloucester Press.
Dyfyniad Arddull ChicagoGardiner, Brian. Energy Demands. London: Gloucester Press, 1990.
Dyfyniad MLAGardiner, Brian. Energy Demands. London: Gloucester Press, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.