Possible regular phenomena in EXO 2030+375 Eva Laplace, Tatehiro Mihara, Yuki Moritani, Motoki Nakajima, Toshihiro Takagi, Kazuo Makishima and Andrea Santangelo A&A, 597 (2017) A124 Published online: 13 January 2017 DOI: 10.1051/0004-6361/201629373