APA (7th ed.) Citation

Caffau, E., Sbordone, L., & Ludwig, H. (2013). X-shooter GTO: Evidence for a population of extremely metal-poor, alpha-poor stars. Astronomy and astrophysics, 560(?), .

Chicago Style (17th ed.) Citation

Caffau, Elisabetta, Luca Sbordone, and Hans-Günter Ludwig. "X-shooter GTO: Evidence for a Population of Extremely Metal-poor, Alpha-poor Stars." Astronomy and Astrophysics 560, no. ? (2013).

MLA (9th ed.) Citation

Caffau, Elisabetta, et al. "X-shooter GTO: Evidence for a Population of Extremely Metal-poor, Alpha-poor Stars." Astronomy and Astrophysics, vol. 560, no. ?, 2013.