Controlled vocabulary, like the Library of Congress subject headings, is used by libraries to organize books for retrieval. Basically they identify what the book is about. The following is a list of Library of Congress subject headings that will help you explore books in the Libraries' collection. I have hyperlinked a few of the more relevant ones for this topic so that you can browse instantly, if you wish.
Library tip: Most academic libraries employ Library of Congress subject headings for cataloguing and organizing information, so you can use these to search just about any library catalogue.
If you are interested in comparative literature (seeing what environmental policy looks like in other parts of the world) you can swap out the geographic location of Canada, to United States, or Asia, or just about anywhere, to see what the library has on the topic.
Here's a screenshot of how these subject heading searches display, using the Environmental policy Canada example:
To find literature related to the environment and public policy, start your search query with either term, then add additional keywords to your search string to focus on particular aspects.
"public policy" AND environ* AND [enter additional search terms to identify what aspect you’re interested in]
environment* polic* AND canada [you can add a geographic term to your search to focus on a country, for example]
environment* AND policy issues AND government [try other phrases that might express policy topics]
Keyword searching works the same whether you're searching the Internet using a search engine, or a research database for articles, or the Libraries' book catalogue. Some searches may work better than others, so it's a good idea to try a few different searches, and it's a good idea to search a few places. Think of the terminology or language used by the authors of your course readings -- this will give you clues around which search terms to use.
Some "best bets" for public policy content are listed on this page.
Here is an example of an actual search run in the GreenFILE database to give you a sense of how you would run your own search. It also shows how many of our databases will rank your results -- usually the default is by relevance.