My book Spatial Strategies (2009, VDM Verlag) is now available online by Amazon.com. It is primarily written for researchers interested in spatial cognition. This is a book based on my PhD research and it presents 5 interesting experiments about how people explore and navigate in physical/virtual/web environments. It also describes a classification algorithm to identify strategies of optimizing between learning and travelling about novel environments.
Direct link: http://amzn.com/3639189930