  We investigate experimentally and theoretically the electron emission in
collisions between He atoms and Li$^{q+}$ (q=1,2) projectiles at
intermediate-high incident energies. We report on measured absolute values of
double differential cross-sections, as a function of the emitted electron
energy and angle, at a collision energy of 440~keV/u. The different
contributions from target-ionisation, projectile-ionisation, and simultaneous
target-projectile ionisation are calculated with the quantum-mechanical
Continuum Distorted Wave and Continuum Distorted Wave -- Eikonal Initial State
models, and with Classical Trajectory Monte Carlo simulations. There is an
overall good agreement of the calculations with the experimental data for
electron emission cross-sections.
