In addition to journal articles & books, you may find other information useful such as white papers and reports from government entities, think tanks and non-profit groups. This page includes local and national government resources, as well as links to selected non-profit entities.
Check out the International Government Information guide to find more infromation beyond the United States.
Congress talks about everything. Even if you think your topic is hyper-local, it's probably something that affects many cities, so try looking for Congressional sources.
The federal government, as well as local and state governments publish a lot of information on their websites. Use Search USA.gov instead of Google to cut down on non-government results. WARNING: Government websites are only searched by USA.gov if they use a .gov, .us or .mil domain. Governments that use .com domains (like St. Louis County) are not included.