Which type of books are considered authoritative sources that students can consult for information not found in textbooks?

Reference books are a vital resource for students seeking authoritative information that may not be covered in standard textbooks. These books, which include encyclopedias, dictionaries, and specific subject-focused works, provide in-depth information, definitions, and contextual insights that give students access to reliable and comprehensible data.

Unlike textbooks, which typically present a structured curriculum and follow educational standards, reference books serve as supplementary materials that students can consult for additional details, clarification, or specialized knowledge. They are designed for quick information retrieval, making them an ideal choice for students needing to deepen their understanding of certain topics or find specific answers.

Resource guides and compendiums may offer valuable information, but they often do not have the same level of scholarly rigor or comprehensive content as reference books. Therefore, for authoritative and credible information, reference books remain the most suitable choice among the options provided.