Παραπομπή σε μορφή APA (7η εκδ.)

Sparks, R. S. J., & Hawkesworth, C. J. (2004). The state of the planet: Frontiers and challenges in geophysics. American Geophysical Union International Union of Geodesy and Geophysics.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Sparks, R. S. J., και C. J. Hawkesworth. The State of the Planet: Frontiers and Challenges in Geophysics. Washington, DC, [S.l.]: American Geophysical Union International Union of Geodesy and Geophysics, 2004.

Παραπομπή σε μορφή MLA (9th εκδ.)

Sparks, R. S. J., και C. J. Hawkesworth. The State of the Planet: Frontiers and Challenges in Geophysics. American Geophysical Union International Union of Geodesy and Geophysics, 2004.