Heinrich Bratscher Vollenweider - Sources?

Hi there!
I came across the Bratscher Vollenweider family line via FamilySearch. I'm apparently a descendant, and I've been trying to follow breadcrumbs to the original source information. Both here and on FamilySearch, I keep coming up empty handed.
Does anyone know where this information is coming from? Would love to verify.

Thanks!
Andrew