I have an old, out-of-print book titled Oak Hill--Cedar Valley Pioneers (published privately, 1956) that I use for as a source for many of my family profiles. It's a collection of biographies about the settlers of those small communities south of Austin, TX in the 1800s. Checking around, I found a few bios in the book that matched WikiTree profiles: George Dittmar]], Daisy Glasscock and [[Hartkopf-6|Friedlieb Hartkopf]]. There are also a couple of "orphan" Glasscock profiles that are in the book.
The book will show up in a Google search, but I can't find an online text of it. I have the bios in digital form on my computer, and would be happy to send them to anyone who wants to take a look at them. None of these people are related to me.