The role of reports in science
Reports from governments, think tanks, pressure groups, NGO's and other stakeholders may be an important source of information in scientific research. Reports may contain:
Sometimes we use the reports because the organisation publishing the report is the subject of our research, e.g. when you write on the UN system. In other cases information from reports is the reason why we start our research. And in yet other cases reports contain scientific analyses which, just like scientific journal articles, are used to strengthen the argument a a paper or thesis. Always be careful with using information in reports as they are often written with the objectives and interests of the publishing or financing organisation in mind.
Searching for reports
Another option is to search Worldcat. Many important reports have been published "officially" and acquired by libraries. In this way they are included in these integrated national and worldwide catalogues. This is not straightforwaird hoewver as these catalogues do not offer options to filter out report. You have to use advanced search and combine search terms indicating your subject as 'keyword' with names of publishing organisations as 'author' as in the screenshot. N.B. Most recent reports will be available on the web so a targeted web search will often be more efficient.
OECD reports are a special case: Utrecht University subscribes to large parts of the OECD iLibrary with many thousands of reports on economics, regional development, science, industry and services, transport, and innovation and environment.
Many organisations publish their own reports on their own website. These are often freely available and findable with web search engines such as Google and Bing.
using filters in your search to find reports in Google