'Drinken vissen water?' ('Do fish drink water?') was first published in 2006. It was written in co-operation with Maarten Frankenhuis (former director of the Artis Zoo, Amsterdam). The book, with short stories about animals from seahorses to elephants, and illustrated by Irene Goede, sold over 20.000 copies in The Netherlands.
'Waar komt de regenboog vandaan' ('Where does the rainbow come from?') is based on monthly lectures for children given by Robbert Dijkgraaf (at present director of the Institute for Advanced Study in Princeton) and many other enthusiastic scientists from Amsterdam.
'De kosmos, in een notendop' ('The cosmos, in a nutshell'), is a book about stars, comets, black holes and other miracles in the cosmos.