A research library is a library which contains an in-depth collection of material on one or several subjects. A research library will generally include an in-depth selection of materials on a particular topic or set of topics and contain primary sources as well as secondary sources. Research libraries are established to meet research needs and as such are stocked with authentic materials with quality content. Research libraries are typically attached to academic or research institutions that specialize in that topic and serve members of that institution. Large university libraries are considered research libraries, and often contain many specialized branch research libraries. The libraries provide research materials for students and staff of these organizations to use and can also publish