APA (7th ed.) Citation

Johnstone, D., Di Francesco, J., & Kirk, H. (2004). An Extinction Threshold for Protostellar Cores in Ophiuchus. The Astrophysical journal, 611(1), L45-L48. https://doi.org/10.1086/423737

Chicago Style (17th ed.) Citation

Johnstone, Doug, James Di Francesco, and Helen Kirk. "An Extinction Threshold for Protostellar Cores in Ophiuchus." The Astrophysical Journal 611, no. 1 (2004): L45-L48. https://doi.org/10.1086/423737.

MLA (9th ed.) Citation

Johnstone, Doug, et al. "An Extinction Threshold for Protostellar Cores in Ophiuchus." The Astrophysical Journal, vol. 611, no. 1, 2004, pp. L45-L48, https://doi.org/10.1086/423737.