The first step in almost all Mexican legal research is to start with a code or law as the Mexican legal system is based on civil law tradition. Mexican codes are divided into subjects. Unfortunately, Mexican codes cannot be searched by keyword, nor do they have indexes. Instead, codes have a short general table of contents, located either at the front or the back of the code. For this reason, Mexican legal research must be done by first thinking broadly about general legal concepts and then working down to more specific issues.
"As an example, the search in the Mexican civil code for the divorce articles would not start with 'divorce' but with 'of persons' since divorce deals with a relationship of persons. Under the 'of Persons' heading you will find divorce, marriage, adoptions, birth registration, death registration, and other matters relating to a person as a legal entity. A person becomes a legal entity at birth and loses this capacity at death."
The second step in conducting Mexican legal research is to locate the relevant doctrina (legal treatises). Doctrina are often organized by code and the articles organized chronologically. Similar to the codes, doctrina have a table of contents, but no index.
The last step, which is optional, is to find relevant jurisprudencia and tesis. Jurisprudencias is established through five consecutive and consistent decisions on a point of law. Tesis are case decisions of note that have persuasive value, but are not binding on lower courts.
This process can be quite difficult because there very few finding tools to help research and locate relevant documents.