S. 21: akg-images/Fototeca Gilardi
S. 47: Heritage Images/Fine Art Images/akg-images
S. 71: akg-images
S. 87: akg-images/fine-art-images
S. 125: akg-images/sciencesource
S. 153: akg-images/Science Source
S. 175: akg-images
S. 219: akg-images/Pictures From History