[Paraview] need book to understand vtk-file formats?

[Torsten Lange]

Hello,

I asked a student to get familiar with vtk formats to later write scripts to 
extract geometry and scalar/property data from a simulation tool to be 
visualized in PARAVIEW.

There are two books offered related to vtk (Textbook and User's Guide). Would 
one of those be helpful for the student? Or are the online sources sufficient? 
Or maybe other books?

Thank you,
Torsten