Dyfyniad APA

(1980). The role of phosphorus in agriculture. Madison, Wis: American Society of Agronomy.

Dyfyniad Arddull Chicago

The Role of Phosphorus in Agriculture. Madison, Wis: American Society of Agronomy, 1980.

Dyfyniad MLA

The Role of Phosphorus in Agriculture. Madison, Wis: American Society of Agronomy, 1980.

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