1 J.P.J. Driessen, S.S.O. de Beek, H.C.W. Beijerinck, E.M. Spain, H.V. Parks, R.. de Vivie-Riedle, and S.R. Leone, Comments on Atomic and Molecular Physics 32, (1996).
1 J.. Schuster, A.. Marte, S.. Amtage, B.. Sang, G.. Rempe, and H.C.W. Beijerinck, Physical Review Letters 87, (2001).
1 H.C.W. Beijerinck, E.. Vredenbregt, R.J.W. Stas, M.. Doery, and J.. Tempelaars, Physical Review A 61, (2000).