Journal article (2004) - J Friml (author) , X. YANG (author) , PJJ Hooykaas (author) , K Palme (author) , R Offringa (author) , M Michniewicz (author) , D. Weijers (author) , A Quint (author) , O Tietz (author) , R Benjamins (author) , PBF Ouwerkerk (author) , K Ljung (author) , G Sandberg (author)