* The fact that as the incident energy increases, the TDCS decreases and shifts towards smaller ejection angles for positron impact is said twice between lines 108 and 115.
The authors did not mention this method for discussions in the manuscript. In earlier publications [Physics Reports 315 (1999) 409 and related references], a fully relativistic distorted-wave Born approximation (rDWBA) has been developed to describe the relativistic ionization processes.