Document repository data model This example shows how books are commonly described in libraries or bookshops. It is meant to facilitate adding new books and, above all, to facilitate retrieval by readers. Usually, you try to find books by title, author or subject (those are the most common access points). Many of the properties used to describe books belong to other entities: this is mostly how relationships are created between elements. One of the book's main properties is the author’s name and, at the same time, every author entity has additional properties such as counting unit, nationality, etc. It is very common to see this model nourished with more types of documents, for instance multimedia files, maps, magazines, etc. The Cyrilla Database gathers information about digital rights laws around the world in multiple languages and allows to retrieve resources by type (legislation, cases, analysis, etc.) and filter them by country and keyword. It is a great example on how to describe laws to facilitate its retrieval. 12