After you run a case law search on Lexis, you can click on Ravel View to see the relationship between cases.
The circles represent individual cases and the lines show the citing relationship between the cases. The larger the circle, the more it has been cited. Also, you can tell the Shepard's treatment of the case based on the colors of the lines (we will cover this next week).
I ran the following search in All Arizona State Cases, Combined to retrieve cases about apparent authority: "apparent authority"
Then, I limited the results to reported cases after 1965 and then clicked on Ravel View.