D'a, ì A., Pinto, C., Del Santo, M., Pintore, F., Soria, R., Robba, A., Ambrosi, E., Alston, W., Barret, D., Fabian, A.C., Fürst, F., Kara, E., Kosec, P., Middleton, M., Roberts, T., Rodriguez-Castillo, G., Walton, D.J., "The chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1", Monthly Notices of the Royal Astronomical Society, 2025