Most of the information is derived from the Reports of Parliament which are available in Dutch on www.overheid.nl/op/index.html. The Yearbook surveys are also available in a consolidated way in a database on www.asser.nl/pil/index.htm.

Although this sets out to be an annual survey, it may also include material which dates from a different parliamentary year from that given in the heading. This has proved to be inevitable in those cases when texts do not become available to the editor until long after their original date of drafting; written submissions to international organizations made by the Netherlands representatives frequently fall into this category.