text: Annie M.G. Schmidt, illustrations: Sieb Posthuma, Querido, 2011
Gouden Penseel 2012 (Golden Brush, best Dutch illustrator)
text: Maria van Donkelaar & Martine van Rooijen, illustrations: Sieb Posthuma, Gottmer Publishers, 2008
Gouden Penseel 2009 (Golden Brush, best Dutch illustrator)
text: Marjet Huiberts, illustrations: Sieb Posthuma, Gottmer Uitgevers, 2006
Zilveren Penseel 2007 (Silver Brush)
text: Annie M.G. Schmidt, illustrations: Sieb Posthuma, Querido, 2011
Gouden Penseel 2012 (Golden Brush, best Dutch illustrator)
text: Maria van Donkelaar & Martine van Rooijen, illustrations: Sieb Posthuma, Gottmer Publishers, 2008
Gouden Penseel 2009 (Golden Brush, best Dutch illustrator)
text: Marjet Huiberts, illustrations: Sieb Posthuma, Gottmer Uitgevers, 2006
Zilveren Penseel 2007 (Silver Brush)