Watch this short video for a quick tutorial on using the University of Iowa Libraries' Smart Search.
The SmartSearch box above will first return results from the University of Iowa Libraries. It will also offer to search UBorrow if you didn't find what you're looking for. UBorrow searches the libraries at all Big Ten universities plus the University of Chicago -- giving you access to 13 of the largest libraries in the United States. Materials requested through UBorrow will arrive and be available for your use in about a week. If you still don't find what you're looking for, try WorldCat. As a note, there are two interfaces for WorldCat with different search algorithms. The first is easier to use and good for general keyword searches, the second is less user-friendly but very accurate for searches on specific fields such as title, author, subject heading, etc.
Pay attention to subject headings. Most anglophone libraries use Library of Congress Subject Headings (LCSH) which, unfortunately, does not always reflect everyday terminology and/or prefers just one of multiple common terms.
For example, Latinos is not a LCSH. Hispanic Americans is, as well as Mexican Americans, Cuban Americans, Brazilian Americans, etc. If you search under Latinos, you will miss a lot that is described as Hispanic Americans. Likewise, if you only search under Hispanic Americans, you will miss a lot described with more specific terms, like Mexican Americans, and vice versa.
In short, be mindful of your search terms and the descriptive terms a library catalog or database might be using.
For a visual example, if you search for dictatorship Chile, the subject heading Chile -- Politics and government -- 1973-1988 (1973-1988 being the time span during which Augusto Pinochet was in power) would be of interest to you. Click through relevant subject headings to find more relevant materials on your topic.
Use Google Books to search your print books!
Do you have a print book without an index? Find the book in Google Books and search it for your topic. Even if the Google Book version is only available in "snippet view", it will still tell you on which pages your search terms appear.