Research, technical, and statistical reports that are not formally published as books or journal articles fall into the category of "grey literature." These documents are considered "grey" because they may be hard to find. Think tanks, lobbying groups, government agencies and inter-governmental organizations are now posting their reports on their websites making the results of their research easier to find. However, since these reports are not necessarily vetted through the scholarly peer-review process, they are considered "grey" literature and should be carefully evaluated.