1. Company website, Calder AG, Switzerland.
2. ERI Inc., Energy Recovery News, April 19, 2004.
3. Company website, Energy Recovery Inc., U.S.A.
4. Improve energy recovery in gas processing plant using an HPT;Oklejas;Hydrocarbon Process.,2005
5. E. Oklejas et al., Advanced high efficiency energy recovery, IDA World Congress, 2005.