In the following sentence:
The sentence mean something like the following:
Except math books, I also like books about history and literature. When I have time, I often keep reading for several hours.
The sentence likely have the following missing structure, if I understand it correctly:
But then I don't understand how 头 works here. It is clear (for me) that it means "read", or at least work as a verb, but according to my dictionary 头 does not work as a verb.
So how does 头 work here? And is my understanding correct here?