In general, remember that adding the phrase (in quotes) "study and teaching" to any topic will generally help you narrow down on materials intended for use by PK-12 teachers. Another way of narrowing your search is to choose JFK Lower Level Curriculum Center from the list of Physical Locations in the catalog's left sidebar, since that will limit your search to materials set aside for use either by teachers or students in a PK-12 classroom.
Remember that ERIC documents often have curricular ideas that can be built on or adapted: don't click peer-reviewed to ensure you see all the types of materials collected in ERIC!
Remember, when using a search engine (like Google or Bing), pair the topic of interest to you with key phrases like "", "", and "", to see what universities, museums, and educators have collected and made available online. Below, I provide a range of sites that provide extensive access to primary source material (text, image, and audio/video) you may find useful: