Try to find those which work best for you. While no search tool is complete, some are comprehensive while others are more selective. Subject Guides Arrange Internet resources by subject or category and provide links to those resources. Search Engines Allow you to type in keywords and phrases.
Search engines vary in their comprehensiveness.
Become familiar with how to do different searches in a few favorite search tools. Use unique words. Try alternative spellings of words. When you search doesn't succeed try a different search tool. Detailed Search Tips Case Sensitivity can be important so use lowercase text in your searches.