Tohutoro APA (7th ed.)

Crichton, M. (1989). Esfera (1 ed.). Emece.

Tohutoru Kātū Chicago (17th ed.)

Crichton, Michael. Esfera. 1 ed. Buenos Aires: Emece, 1989.

Tohutoro MLA (9th ed.)

Crichton, Michael. Esfera. 1 ed. Emece, 1989.