Dyfyniad APA

Geology Rocks Soil {Express Edition}. Raintree Publishers.

Dyfyniad Arddull Chicago

Geology Rocks Soil {Express Edition}. Raintree Publishers.

Dyfyniad MLA

Geology Rocks Soil {Express Edition}. Raintree Publishers.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.