Books on real estate market valuation

[Mikkel Eliasen]

Hi there,

I am looking for some solid books on valuation and finance of real estate in general. Question I seek to answer are such as 1) what is a good cap-rate relative to the risk free rate/mortage rate? How to determine potential bubbles or overvalued/undervalued markets etc. 

I am from northern europe where caprates typically lie in 2.5-3% range at the moment, hence my asking. 

Does anybody know, where I might get such questions answered?