Accurate positions for the ultraluminous X-ray sources NGC 7319-X4 and NGC 5474-X1 and limiting magnitudes for their optical counterpartsDOI: info:10.1111/j.1365-2966.2012.21370.xv. 4241563–1569
Heida, M., Jonker, P. G., Torres, M. A. P., and Mineo, S. 2012. "Accurate positions for the ultraluminous X-ray sources NGC 7319-X4 and NGC 5474-X1 and limiting magnitudes for their optical counterparts." Monthly Notices of the Royal Astronomical Society, 424 1563–1569. https://doi.org/10.1111/j.1365-2966.2012.21370.x.