Maastricht and Amsterdam (the later 1980s to the late 1990s)

The Europa website provides an overview of the Treaty on European Union (the Maastricht Treaty):
https://www.europarl.europa.eu/about-parliament/en/in-the-past/the-parliament-and-the-treaties/maastricht-treaty

The Europa website provides an overview of economic and monetary union:
https://ec.europa.eu/info/business-economy-euro/economic-and-fiscal-policy-coordination/economic-and-monetary-union_en

The Europa website provides an overview of the Treaty of Amsterdam:
https://www.europarl.europa.eu/about-parliament/en/in-the-past/the-parliament-and-the-treaties/treaty-of-amsterdam

The Presidency conclusions of the Amsterdam European Council meeting of June 1997 discuss the conclusions of the IGC that agreed the text of the Treaty of Amsterdam. The conclusions can be found at:
www.consilium.europa.eu/ueDocs/cms_Data/docs/pressData/en/ec/032a0006.htm