When studying, it a good idea to incorporate a variety of sources into your review. Use the textbook, the lectures and the handouts given by your professional. You also want to review the internet and any audiovisual material that is suggested. It may help for you to get interviews or read biographies of the people you are studying. Many people use fiction to get an idea of an historical time period or event. Original source material will be invaluable in your study.
It has been found that using more than one source while studying increases understanding and retention, providing the sources are used properly.
Sometimes one textbook is too hard to understand, and another source is needed. If you use other readings, you may get a broader understanding of the topic. Just be sure to analyze the readings carefully, especially if information does not agree. When you have information that does not agree with other information, take a few minutes to read and evaluate it. Try to use the material with your text in order to create a more accurate overall picture. Other sources will give you more facts and source material about your topic. Be sure to know the vocabulary in all your sources.
Go ahead and read your text then read other sources. Try to understand the similarities and differences in the texts. It may be helpful to use online sources to discuss the material.