This appears to be a translation of a German book written by Karl Ochsner. Most of the pictures of heat pump systems in the book are Ochsner heat pumps, so it's a fair assumption the author runs a business designing and selling heat pump systems. The book is relatively short, 146 pages including indices. A lecturer lent me his book for a week (I am a postgraduate student). It's not an exciting read, but I had no trouble getting through it or understanding it. It looked like it could be useful so I bought my own copy. It contains descriptions of a number of different heat pump types, including ground source, water source and air source systems, and their main components. It has a lot of technical detail and practical information for designing and installing heat pump systems. It starts with a couple of chapters on background and theory and then gets down to the nitty gritty. It covers space and water heating systems and also cooling.
There are so few accessble books on the subject of geothermal heatpumps that nothing else comes close. Most of the subject matter is covered as part of generic books on alternative energy, whereas this covers everything from deciding whether it really makes sense to install a geothermal heat pump to how to do it. We're about to start an installation and this book will allow me to have informed discussions with salesmen and installers without having any wool pulled over my eyes. What's more the style of the book (for what could be a dry subject) is far easier than the simple title would suggest. A must for anyone seriously contemplating geothermal heating. Despite its somewhat high price, I have no doubt it will save that value many, many times over in the system cost and the ongoing energy savings.