Have you set up WikiTree profiles for Kost, Maria, or Mike? That's a good place to start, so anyone hoping to help you can see what you already know.
Did any of them immigrate to North America? From most censuses, you can find out their year of immigration. Depending on where and when they arrived, a ship's record could list other information such as the last place they lived, or the address of the next of kin living in their old country, or the address of someone they are meeting in the new one. A good place to start is Ancestry.com. If you don't have your own account, a lot of public libraries have access to the collections.
Hope this helps!