Dyfyniad APA

Fortey, R. A., & Bruton, D. L. (2013). Lower Ordovician trilobites of the Kirtonryggen Formation, Spitsbergen. Wiley Blackwell.

Dyfyniad Arddull Chicago

Fortey, Richard A., and David L. Bruton. Lower Ordovician Trilobites of the Kirtonryggen Formation, Spitsbergen. Hoboken, New Jersey: Wiley Blackwell, 2013.

Dyfyniad MLA

Fortey, Richard A., and David L. Bruton. Lower Ordovician Trilobites of the Kirtonryggen Formation, Spitsbergen. Wiley Blackwell, 2013.

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