1. Economic possibilities and limitations of heat pumps with electric drive;Lorentzen,1978
2. The economics of heat pump systems for simultaneous heating and cooling;Gosh;Heat Recovery Systems and CHP,1987
3. The economics of industrial heat pump systems for simultaneous heating and cooling, Heat Pumps. Solving energy and environmental challenges;Zheng,1990
4. Compression-absorption cycles with R22/E181 and NH3/H2O;Ziegler,1991
5. Wärme-Kälte-Kopplung in einer Käserei;Ziegler,1997