What qualifies as a "primary" source... 

discussion & considerations

examples

Exploring the dimensions of the topic...

key words and concepts

broader, narrower, related

questions that arise as you go

keeping a journal for your paper

Where to look for scholarly, secondary sources depends on the nature and scope of your topic...

Tracing the scholarly conversation...

One useful work may help to locate others. For example:

Look at references (footnotes, endnotes, bibliography) to trace the sources the author used...

In this case, a cited book is found in the Library' print book collection.

Book:

Tracing sources forward using Google Scholar "cited by":

Selected resources for Chicago Style help...