Bruce, A., Lawrence, A., MacLeod, C., Elvis, M., Ward, M.J., Collinson, J.S., Gezari, S., Marshall, P.J., Lam, M.C., Kotak, R., Inserra, C., Polshaw, J., Kaiser, N., Kudritzki, R-P., Magnier, E.A., Waters, C., "Spectral analysis of four ‘hypervariable’ AGN: a micro-needle in the haystack?", Monthly Notices of the Royal Astronomical Society, 2017