Cita APA (7a ed.)

Riccardi, A. C., Westermann, G. E. G., & Elmi, S. (1991). Biostratigraphy of the upper Bajocian-middle Callovian (Middle Jurassic), South America.

Cita Chicago Style (17a ed.)

Riccardi, Alberto Carlos, G. E. G. Westermann, y S. Elmi. Biostratigraphy of the Upper Bajocian-middle Callovian (Middle Jurassic), South America. 1991.

Cita MLA (8a ed.)

Riccardi, Alberto Carlos, et al. Biostratigraphy of the Upper Bajocian-middle Callovian (Middle Jurassic), South America. 1991.