There are a lot of options for expanding your research. Which is the best is going to depend on your topic.
We have databases that play the same role as America: History and Life and Historical Abstracts for almost every field of study. A few examples given below, but you can find more through our database listings (use the subject pull-down menu).
Cross searches all the databases mentioned so far, plus many more.
Google algorithm and search interface are very different from what library databases use. Sometimes this is a good thing!