[en] Inclusive cross sections for the emission of ⁶He and ^6,7,8Li at laboratory angles of 45 deg, 90 deg and 135 deg in ⁴He collisions with Ag and Au targets at a beam kinetic energy of 3.33 GeV/nucleon are presented. Assuming the existence of an intermediate object emitting secondary particles, its velocity and temperature for different fragment energies have been founded. The ratios of the spectra of ⁶He to ⁶Li and ⁷Li to ⁶Li are considered. It has been shown that the inclusive cross sections can be successfully described assuming the existence of two mechanisms of fragment emission: the evaporation of slow fragments from the residual nucleus and the decay of fireball-like objects. No qualitative difference has been found between the production processes of the lightest (A_f=1-4) and medium-mass (A_f=6-8) fragments