Journal article (2015) - E Marien (author), M Meister (author), M Bagadi (author), H Dienemann (author), M Thomas (author), PA Schnabel (author), RM Caprioloi (author), E Waelkens (author), JV Swinnen (author), T Muley (author), S Fieuws (author), S Bordel (author), R Derua (author), J Spraggins (author), Raf Van de Plas (author), J Dehairs (author), J Wouters (author)

Report (1997) - J Dijk (author), J Wouters (author), JFH Hiethaar (author)