Reference books published annually, bi-annually, or semi-annually are also referred to as

### Why this is right A **serial** is a publication issued in successive parts over time, usually at stated intervals and with no fixed final issue planned. Since the books in the question are published repeatedly each year, they fit this category. ### The concept Serials can appear daily, monthly, annually, or at other regular intervals. The term describes how a publication is issued, rather than the subject it covers or the way it is used. Examples include journals, magazines, yearbooks, and directories that are updated in new editions over time. A handbook is instead a book of useful facts or guidance, while a manual usually gives instructions for doing something. ### The other options - **A. Handbook**: A handbook provides facts or guidance on a subject. It may be updated, but the word does not specifically mean a publication issued in successive parts. - **B. Manual**: A manual gives instructions on how to use, operate, or do something. It describes the content or purpose, not a recurring publication schedule. - **D. Prospectus**: A prospectus is a document presenting plans or information, often about an educational institution, investment, or proposed project. It is not the general term for regularly issued reference books. ### Terms - **Serial**: A publication issued in successive parts over time, usually at regular intervals, with no set end planned. - **Handbook**: A compact reference book containing useful facts or guidance on a subject. - **Manual**: A document or book that explains how to do something or use something. - **Prospectus**: A document describing a plan, organization, course, or investment to inform potential participants or investors. ### Remember If a publication continues to appear in new issues or editions at regular intervals, think **serial**.