The Author Finder works well for authors with common names. If you are searching for an author with a unique name or feel that the Author Finder has missed something, try an author search from the main search page. Be sure to select Author from the search drop down.
The results of an Author Search for Spitzer, L* is shown below. Looking at the first article, we can see there are results by other authors named L. Spitzer. To narrow results to only those articles by Lyman Spitzer, click on the 'more options/values' link under Web of Science Categories.
Check the box next to the relevant categories, then click Refine to narrow the results.
This search returned the same number of articles as the Author Finder.