Treaty on the European Union (TEU) & Treaty on the Functioning of the European Union (TFEU)

Treaty Change
Art. 48 TEU [Ordinary Revision Procedure & Simplified Revision Procedures]

Free Movement & Citizenship
Title II TFEU [Free Movement of Goods]
Title IV TFEU [Free Movement of Persons, Services and Capital]
Art. 20 TFEU [Citizenship of the Union]

Approximation of Laws & Legislative Procedures
Chapter III, TFEU [Approximation of Laws]
Chapter II, Section 2 [Procedures for the Adoption of Acts and Other Provisions]
Art. 352 TFEU [Flexibility Clause]

Enhanced Cooperation
Title IV TEU [Provisions on Enhanced Cooperation]
Title III TFEU [Enhanced Cooperation]