The Max Planck Encyclopedia includes the following chapters:
Labour Law, International by Franz Christian Ebert & Claire La Hovary - This chapter includes sections on historical development, sources of international labour Law & selected areas of international labour law.
Work, Right to, International Protection by Angelika Nußberger - this chapter includes sections on the historical development of the right to work (in national constitutions and international law - including binding international instruments and soft law), the definition and nature of the right to work, Comments and Jurisprudence on the Right to Work, the Major Components of the Right to Work, Protection of the Right to Work of Vulnerable Groups, and Actual Trends and Developments on the National and International Levels.
International Labour Organization (ILO) by Heiko Sauer - This chapter includes the historical background and development of the ILO, its basic Features and special legal problems, its relationship with other international organisations, and an evaluation of the organisation.
The Kluwer Encyclopaedia of Labour Law includes:
NOTE: While these publications are a good starting point for your research, some of the commentaries is several years old, so the law may have changed - so be aware that you may need to check eg: national legislation on official government legislation websites to ensure currency, and the ILO databases for up to date status of conventions and recent case law.