Dyfyniad APA

(1982). Methods of soil analysis. Wisconsin: American Society of Agronomy, Inc.

Dyfyniad Arddull Chicago

Methods of Soil Analysis. Wisconsin: American Society of Agronomy, Inc, 1982.

Dyfyniad MLA

Methods of Soil Analysis. Wisconsin: American Society of Agronomy, Inc, 1982.

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