Dyfyniad APA

Oluf Chr. Bockman. (1990). Agriculture and fertilizers: Fertilizers in perspective. Norway: Norsk Hydro a.s.

Dyfyniad Arddull Chicago

Oluf Chr. Bockman. Agriculture and Fertilizers: Fertilizers in Perspective. Norway: Norsk Hydro a.s, 1990.

Dyfyniad MLA

Oluf Chr. Bockman. Agriculture and Fertilizers: Fertilizers in Perspective. Norway: Norsk Hydro a.s, 1990.

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