The American historian John Van Antwerp Fine , Jr. writes that , if Zlatarski 's theory is correct , Kuber was named for his father .
Kuber and Kubrat are most probably two Greek versions of the same Bulgar name .
The American historian John Van Antwerp Fine , Jr. writes that , if Zlatarski 's theory is correct , Kuber was named for his father , because Kuber and Kubrat are most probably two Greek versions of the same Bulgar name .