After locating applicable treaties and organizations using encyclopedias, you can use handbooks and scholarly commentaries to deepen your understanding of the legal texts.

Commentaries:  these provide article-by-article analysis of a legal text.  In LawCat, search [name of the agreement] commentary

• The Charter of the United Nations: A Commentary (Bruno Simma ed., 3rd ed., 2012).
• The International Covenant on Civil and Political Rights : cases, materials, and commentary (Sarah Joseph and Melissa Castan, eds. 2013).
• Rachel Murray, African Charter on Human and Peoples' Rights: A Commentary (2019).

Handbooks:

• Handbook of Human Rights (Thomas Cushman ed., 2012).
• Research Handbook on Human Rights and Humanitarian Law (Robert Kolb ed., 2013).
• Handbook on the European Convention on Human Rights (Mark Villiger, 2023)

• Routledge Handbook of Human Rights in Asia (2019).

• The Oxford Handbook of International Human Rights Law (Dinah Shelton ed., 2013).

• Sarah Joseph and Adam McBeth, Research Handbook on International Human Rights Law (2010).