The 54-day orbital period of AX J1820.5–1434 unveiled by SwiftA. Segreto, V. La Parola, G. Cusumano, A. D’Aì, N. Masetti and S. CampanaA&A, 558 (2013) A99DOI: https://doi.org/10.1051/0004-6361/201321892
