Reference books are usually encyclopedias, dictionaries, handbooks, atlases, etc. They are intended to provide quick, reliable information, summaries of complex matters, and, very importantly, bibliographies--suggestions for futher reading.Some are in print; others online.
These reference materials are customarily written by experts in their fields, so they are more trustworthy than Wikipedia--all have gone through a process of editorial review. For an illustrated explanation, see the home page presentation, "What is a referred or scholarly article?"
Print & online sources:
Encyclopedia of Native American Tribes Ref. E76.2.W35 1999
Encyclopedia of North American Indians Ref E76.2.E53 1997
Encyclopedia of North American Indians (online)
Handbook of North American Indians Ref E77.H36. Library has volumes 2-15 & 17.
Native Americans: An Encyclopedia of History, Culture, and Peoples Ref E77.P89 1998
Bibliography of Native North Americans (Online)
Covers
books, essays, journal articles, and government documents on native
North American history and culture from pre-history to the present,
1800-present.
The Encyclopedia of Ethnic Groups in Hollywood Ref PN1995.9.M56M85 2003
Multicultural Films: A Reference Guide Ref PN1995.9.M56W45 2005
Within Our Gates: Ethnicity in American Feature Films, 1911-1960 Ref PN1995.9.M56W58 1997