Excitation of 2 1S, 2 1P and 3 1P, 3 3P levels of helium in He+ on He collisions at a few hundreds eV G. Rahmat, G. Vassilev et J. Baudon J. Phys. France, 41 4 (1980) 319-333 DOI: 10.1051/jphys:01980004104031900