1. V. Palm, Rev. Sci. Instrum., 70, 7, 2957–2959, (1999).
2. K.K. Rebane, O. Ollikainen, V.V. Palm, Opt. Spectrosc. (USA), 84, 3, 374–380, (1998) [Transi, of Opt. Spektrosk. (St. Petersburg), 84, 3, 431-438, (1998)].
3. N. Caspary, V. Palm, K.K. Rebane, V.E. Bondybey, Chem. Phys. Lett., 283, 5-6, 345–349, (1998).
4. V. Palm, K. Rebane, J.Lumin., 86, 3-4, 207–209, (2000).