Dyfyniad APA

Gorle Peter & James Long. (1973). Essentials of product planning. McGraw hill.

Dyfyniad Arddull Chicago

Gorle Peter and James Long. Essentials of Product Planning. London: McGraw hill, 1973.

Dyfyniad MLA

Gorle Peter and James Long. Essentials of Product Planning. McGraw hill, 1973.

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