Tacconi, L. J. Infrared and Submillimeter Astronomy, MPI for Extraterrestrial Physics, Max Planck Society;
Guélin, M., Salomé, P., Neri, R., García-Burillo, S., Graciá-Carpio, J., Cernicharo, J., et al. (2007). Detection of HNC and tentative detection of CN at z = 3.9. Astronomy & Astrophysics, 462(3), L45-L48. doi:10.1051/0004-6361:20066555.