1. Dictionary of refrigeration and air conditioning;K. MC.,1970
2. British Standards InstitutionThermally insulating underground piping systems, BSI, London, 1973
3. CARLSSON, S. and ENEBORG, I., Heat losses from culverted pipelines (in Swedish), No.42, Swedish State Building Research Est, 1963
4. Refrigeration, air conditioning and cold storage;GUNTHER,1973
5. Thermal insulation in cryogenic engineering;KAGANER,1969