Using specialized encyclopedias to become familiar with your topic is the most efficient way to get started on your research. These encyclopedias, written by knowledgeable scholars, will summarize your topic, provide you with social and historical context, familiarize you with specialized terminology, and often provide lists of additional resources on your topic. They are providing you in condensed form information from multiple books and articles. Think of them as CliffsNotes ... that you are allowed to use.
This search in OskiCat will retrieve relevant encyclopedias.
Bibliographies can also be research tools that bring together in one location (either print or electronic) citations from articles, books, book chapters, disserations, conference proceedings, primary matierials, and other academic sources about a specific topic. That topic might be broad, such as "Medieval history" or very narrow, such as "Red-haired women mentioned in courtly litearature."
This search in OskiCat will retrieve items with the keyword hispanic along with words that start with immigra*. It will also only retrieve items that have the word bibliography in the subject field.