The keyword phrase "september 11th books" functions as a noun phrase. The core component and main point of this phrase is the noun "books." The term "September 11th" acts as a modifier, specifying the subject matter of the books.
In this grammatical construction, "September 11th," which is a proper noun referring to a specific date and historical event, is used as a noun adjunct (or attributive noun). A noun adjunct is a noun that modifies another noun, effectively functioning as an adjective. It answers the question "What kind of books?" The answer is books pertaining to the topic of September 11th. This is a common structure in English, similar to phrases like "history textbook" or "kitchen counter," where "history" and "kitchen" modify "textbook" and "counter," respectively.
Therefore, for the purpose of the article, the primary part of speech to consider as the main point is the noun "books." The article's central theme is a collection of literary or informational works. The modifier "September 11th" defines the specific category or topic of those works, establishing the scope and focus of the content.
