Where can I find VCF files of the same source

In order to see if one of mine application works as expected, I need VCF files (at least 2) of the same person covering the same region of the genome. I think that around 40 samples (20 people) would be enough.

Reason:
I have developed an application that says if two VCF files belong to the same patient by comparing the variants of both files. I need the sample to check the percentage of similarity and then compare these results with the results obtained from VCF files of different people.