There are two ways to refine your search and focus on clinical trials:
A. The 
icon is displayed next to relationships that at least one clinical trial exists, coming directly from clinicaltrials.gov. To refine for those trials, use the Data Source filter from the filters panel (Figure 1).
Figure 1: The Data Source filter
B. Alternatively, you can look for clinical trials published in any Data Source that Causaly machine-reads and select "Clinical Trial" under the Publication Type filter (Figure 2).
Figure 2: The Publication Type filter