| iso.ch | ISO. International Organization for Standardization |
| hrai.ca | Hrai - The Heating, Refrigeration And Air Conditioning Institute Of Canada |
| epri.com | Epri.com |
| cti.org | Cooling Technology Institute |
| cibse.org | Chartered Institution of Building Services Engineers (CIBSE) |
| ashrae.org | American Society of Heating, Refrigerating, and Air-Conditioning Engineers |
| hvacexcellence.org | Program Accreditation and Technician Certification |
| siki.se | VVS-Tekniska Föreningen |
| scanvac.net | Scanvac |
| rses.org | Refrigeration Service Engineers Society |
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