1. Analysis of the trans-critical vapour compression cycle used for heat pumps;Nekså,1992
2. Recent advances in CO2 refrigeration;Pettersen,1995
3. Konsekvenser ved overgang til CO2 som kuldemedium i kuldeanlegg og varmepumper (in Norwegian);Nekså,1996
4. CO2 as a heat pump working fluid for retrofitting hydronic heating systems in Western Europe;Kruse,1997
5. CO2 in the low temperature stage of large industrial refrigeration plants;Brendeng,1997