López, K., Heida, M., Jonker, P., Torres, M., Roberts, T., Walton, D., …Harrison, F. (2017). A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II). Monthly Notices of the Royal Astronomical Society, 469(1), 671-682. https://doi.org/10.1093/mnras/stx857