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.