APA (7th ed.) Citation

Helfenstein, P., Veverka, J., Thomas, P., Simonelli, D., Lee, P., Klaasen, K., . . . Murchie, S. Galileo Photometry of Asteroid 951 Gaspra. Elsevier.

Chicago Style (17th ed.) Citation

Helfenstein, P., et al. Galileo Photometry of Asteroid 951 Gaspra. Amsterdam: Elsevier.

MLA (9th ed.) Citation

Helfenstein, P., et al. Galileo Photometry of Asteroid 951 Gaspra. Elsevier.