Q:

Textbooks in A Kingdom for Keflings

In the game A Kingdom for Keflings, you can find some textbooks.   So far I've found 2.   I can not for the life of me figure out what they are for.   What do you do with the text books? 

A:

They're used for constructing certain buildings, such as the primary school and the secondary school.  
Three are on the map, sometimes under resources.  You also get one each time you finish building something that needs one. 