[Ger-Poland-Volhynia] Roehlich/Busse Family

[Tammy Jochman]

I found a marriage record in the Volhynia Database for Peter Roehlich & Wilhelmine (nee Busse) marriage date Feb 4 1892 in Rozyszcze.
 
I am trying to find out information on their adoptive daughters Auguste & Marie. 
Auguste is my great-grandmother. It is likely that the Roehlich's were neighbors/friends to Auguste & Marie's biological parents.  
Peter and Wilhelmine took the girls to the US where they lived in MI. 

How do I go about finding more details on the marriage record for Peter & Wilhelmine? 

Do you have any suggestions on how to research a private adoption in 1892 in Volhynia?

Thanks you for any suggestions!
Tammy Jochman