This necessitates sifting through material that is indexed in broad cross-disciplinary databases, such as Academic Search . Foreign language materials are useful and may be a large part of what is published. The accumulated record of past research and interpretation continues to be important with the need for evaluation considering time period of publication. This may include interviews, historical documents, field notes, archives, artifacts, data sets, statistics. These are typically not formally published, but articles published in the popular press may be used when studying popular culture.
Secondary sources covers all other published material.
The most important sources for research papers are scholarly journal article and book publications, which document, summarize or interpret primary or original research. For help in identifying scholarly articles, link to the web page Characteristics of Scholarly and Popular Magazines . Indexes and bibliographies These are valuable sources for identifying research publications, as well as popular published material. These make up a specialized type of secondary source. Reviews articles can be either lengthy overviews of a particular issue or area of research or reviews of particular publication.