A family of Microsoft word processing software products for creating web, email, and print documents.
Place the common text in a separate document. Then in each of the booklet documents, insert an INCLUDETEXT field that contains the path and filename of the common text document. When that field is updated, it will pull in the text from the common text document. Read https://wordmvp.com/FAQs/TblsFldsFms/includetextfields.htm for instructions.
If there's a chance that you may want to move the documents to a different folder or drive, or to a cloud storage location, refer to https://www.msofficeforums.com/word/38722-word-fields-relative-paths-external-files.html for a way to avoid having to change the path in the fields.