Variability in the cycle length of the supersoft source RX J0513.9-6951V. Burwitz, K. Reinsch, J. Greiner, E. Meyer-Hofmeister, F. Meyer, F. M. Walter and R. E. MennickentA&A, 481 1 (2008) 193-198DOI: https://doi.org/10.1051/0004-6361:20067010
