- Smithsonian Institution, National Postal Museum,
- American Memory, Library of Congress http://memory.loc.gov/ammem/
- Differentiating Sources http://memory.loc.gov/ammem/ndlpedu/start/prim_sources.html.
- MLA documentation style for Internet sources
- Lesson to help students gain skills necessary for researching by locating credible and original sources, determining if the sources are primary or secondary, ascertaining the qualifications and reputation of the author/speaker, and identifying the setting/circumstance of the source.
- Finding Primary Sources in Library Research
- National Archives http://www.archives.gov/.
- Specific site for teachers and students completing a History Day project http://www.archives.gov/education/history-day/index.html
- National History Day http://www.nationalhistoryday.org/
- Delaware History Day http://www.hsd.org/histday.htm
- Using Primary Sources on the Web http://www.lib.washington.edu/subject/history/RUSA/
- Researching History Day topics and differentiating between types of sources http://www.lib.washington.edu/subject/history/historyday/his.html