Of course, the actual number of sources required may be more or less depending on your specific topic or the length of your annotated bibliography. For example, if you are researching a very specific topic, you may only need a few sources in order to provide a comprehensive overview. Conversely, if you are writing a longer annotated bibliography, you may want to include more sources in order to provide a more thorough analysis of your topic.
Ultimately, the best way to determine how many sources you need for your annotated bibliography is to consult with your instructor or advisor. They can help you determine the scope and depth of your research project and recommend the appropriate number of sources.