Lettinga, M. P. [P:(DE-Juel1)130797] ; Koenderink, G. H. [P:(DE-HGF)0] ; Kuipers, B. W. M. [P:(DE-HGF)0] ; Bessels, E. [P:(DE-HGF)0] ; Philipse, R. H. [P:(DE-HGF)0]