Journal article (2013) - PHJ Kouwer (author), M Koepf (author), S.J. Picken (author), RJM Nolte (author), E. Mendes (author), AE Rowan (author), V.A.A. le Sage (author), M Jaspers (author), AM van Buul (author), ZH Eksteen-Akeroyd (author), T Woltinge (author), E Schwartz (author), HJ Kitto (author), R Hoogenboom (author)

Journal article (2007) - PHJ Kouwer (author), S.J. Picken (author), GH Mehl (author)