Searching UC Library Search, you will want to restrict to "Available online" on the left sidebar and to books or videos or websites, etc and may want to enter subject headings or keywords such as:
Cities and towns
Name of City - history
Urbanization - Country - City - example (Urbanization - Korea (South) - Seoul
Urbanization - Political aspects (or Social aspects)
and then restrict to "available online" and sort so that you get the newest content loaded first.
Or you can use any of the Reference Guides listed below
This long list of resources provides coverage for both US cities and international cities. Based on population, demographic analysis, environmental and geographical frameworks, the socio-economic coverage, specific coverage for history and other elements of social change can be found using a variety of these sources. Make sure that you consult a variety of sources and verify the dates that the data reflects because those details dictate the accuracy of your research and reporting.
The top of the list contains sources for US followed by international and then resources about cities including reference works, indexing sources that will take you to journal articles and other references.