Cita APA

Smith, A. B., Gallemí, J., Jeffery, C. H., Ernst, G., & Ward, P. D. (1999). Late Cretaceous-early terciary echinoids from northern Spain: Implications for the Cretaceous- Tertiary extinction event.

Citación estilo Chicago

Smith, A. B., Jaume Gallemí, C. H. Jeffery, G. Ernst, y P. D. Ward. Late Cretaceous-early Terciary Echinoids From Northern Spain: Implications for the Cretaceous- Tertiary Extinction Event. 1999.

Cita MLA

Smith, A. B., et al. Late Cretaceous-early Terciary Echinoids From Northern Spain: Implications for the Cretaceous- Tertiary Extinction Event. 1999.