PROGRAMS for REFRIGERATION & AIR CONDITIONING PROFESSIONALS by MISTRAL
If the URL was a 'cached' old link or maybe given to you by someone else then the link could very likely not have worked.
Why? Mistral's team of engineers and programmers update databases on a daily basis and programs are also upgraded as a constant process of improvement. Links therefore 'expire' very quickly and you will need to return to Mistral's home page and browse again from there.
All part of the exceptionally high quality of service that subscribers deserve and have come to expect from Mistral and which all subscribers contribute to with their Licence Fees!