You don't have to tell me. Attribute agency where it is due. A book does not discuss nor are a variety of issues discussed in books.
Authors do the explaining, exploring, arguing, examining, refuting, etc.
Avoid discuss . Verb Tenses Use past tense to refer to historical events. Among southeastern peoples, Indian women were responsible for most of the agricultural labor. George Washington was the first president of the United States. There is, however, a very important exception to this rule.