Organizations, institutions and governments are constantly publishing reports. Although reports are not scholarly publications, they can still contain important information which you can use for your research.
It is often hard to work out when these reports were published or whether they are still available. Libraries also collect reports, but this is often a haphazard undertaking. Usually reports are hard to find in bibliographic databases. That is why we tend to refer to reports and similar literature as 'grey' literature.
Nevertheless, it is possible to find grey literature.
You can also search in SmartCat. Many important reports are ‘officially’ published and included in catalogues.
The GLIN (Grey literature in the Netherlands) database contains the titles of all publications by governing bodies, academic institutions and comparable organizations published in the Netherlands.
Many organizations publish their reports on their websites. The reports are freely accessible and can be found using important search engines such as Google and Google Scholar.