The Citing articles tool gives a list of articles citing the current article. The citing articles come from EDP Sciences database, as well as other publishers participating in CrossRef Cited-by Linking Program. You can set up your personal account to receive an email alert each time this article is cited by a new article (see the menu on the right-hand side of the abstract page).
Virginia Trimble and Markus J. Aschwanden Publications of the Astronomical Society of the Pacific 116(817) 187 (2004) https://doi.org/10.1086/383241
QSOs and Active Galactic Nuclei Associated with NGC 2639
E. Margaret Burbidge, Geoffrey Burbidge, Halton C. Arp and Stefano Zibetti The Astrophysical Journal Supplement Series 153(1) 159 (2004) https://doi.org/10.1086/421465
New optical spectra and general discussion on the nature of ULXs