Spectral evolution of X-ray pulsar 4U 1901+03 during the 2019 outburst based on Insight-HXMT and NuSTAR observations
Armin Nabizadeh, Sergey S. Tsygankov, Long Ji, Victor Doroshenko, Sergey V. Molkov, Youli Tuo, Shuang-Nan Zhang, Fan-Jun Lu, Shu Zhang and Juri Poutanen