Thank you for this. I see that ETOROVIC is usually a last name, and in 1907 he entered the US with ETOROVIC KOSTA, but only used KOSTA. Not knowing his siblings means he might have taken his father's KOSTA, but the ETOROVIC will be seen in time (if there are indeed, any records or DNA matches). I thank you for this very helpful answer. Blessings from Australia. kg