This book is conceived as an educational material through which researchers, university professors, undergraduate and graduate students, and research assistants will be able to know (or expand their knowledge) about citation managers, so that they can be motivated to use them as research tools. Therefore, this book is not a manual as it does not provide instructions regarding the usage of any particular citation manager. Instead, it shows general aspects about these tools, in order to motivate its readers to make their own decisions based on their particular needs.