https://wmo.int/media/news/iom-report-fifth-wmo-regional-pyrheliometer-comparison-of-ra-ii-held-jointly-ra-v
The report on the Fifth WMO Regional Pyrheliometer Comparison of RA II, held jointly with RA V is published as an Instruments and Observing Methods (IOM)...
iom reportfifthwmoregionalpyrheliometer