Locate additional resources by searching google. Please keep in mind whether the source is credible. This guide from Purdue provides some points to consider:
https://owl.purdue.edu/owl/research_and_citation/conducting_research/evaluating_sources_of_information/general_guidelines.html
1. limit document type by using site:
site: gov = government publications (federal, state, local and government sponsored research)
site:edu = educational sites
site:org = organizations, associations
examples:
Black Panthers site:gov
National Archives
https://www.archives.gov/research/african-americans/black-power/black-panthers
Library of Congress
https://www.loc.gov/collections/civil-rights-history-project/?fa=subject%3Ablack+panther+party
"the Black Hand" site:org
International Encyclopedia of the First World War
https://encyclopedia.1914-1918-online.net/article/black_hand/2016-09-15
2. see if other libguides are available:
keywords libgude
Black Panthers libguide
https://cnu.libguides.com/psthe1960s/blackpanther
https://research.pugetsound.edu/blackpantherparty
3. Use Wikipedia - BUT only for the references!
