“…The high energy string scattering amplitudes in the GR [1, 2, 3] were recently intensively reinvestigated for massive string states at arbitrary mass levels [4,5,6,7,8,9,10,11,12]. See also the developments in [13,14,15]. An infinite number of linear relations, or stringy symmetries, among string scattering amplitudes of different string states were obtained.…”