1. L.G.J. de Haart and G. Blasse, J. Solid State Chem., in press.
2. H.C.G. Verhaar, H. Donker, G.J. Dirksen, M.J.J. Lammers, G. Blasse, C.C. Torardi and L.H. Brixner, J. Solid State Chem., in press.
3. L.G.J. de Haart and G. Blasse, J. Solid State Chem., submitted
4. KxRb1−xTiOPO4: A new nonlinear optical material