Engel, H., Davies, R. I., Genzel, R., Tacconi, L. J., Sturm, E., & Downes, D. (2011). Arp 220: extinction and merger-induced star formation. The Astrophysical Journal, 729(1): 58, pp. 1-14. doi:10.1088/0004-637X/729/1/58.