National libraries are tasked with the centuries-long responsibility of preserving books and documents that keep a country’s history and heritage safe through war, disaster, and the passage of time. They’re also responsible for sharing these vast and valuable documents with citizens of the country, and the world.
National libraries are the absolute best resource for finding publications within any given country. This is thanks to legal deposit, legislation in many countries that requires publishers to provide the national library with a copy of each publication. In some countries, this even includes digital publications.
Through national library catalogs, you can search all of the publications within a country. Many national libraries also offer extensive digital collections, offering online researchers access to documents of historical importance, official publications, even images and video.
via Worldwide National Library Catalogs – OEDB.org.
The post provides a comprehensive list of Worldwide National Library Catalogs, including 3 from Canada.