Complex sentence: Bijelo Brdo culture is dated to more than one hundred years later and a theory about "remnant Avar group" in Slovakia in the second half of the 9th century also suffers chronological and geographical problems.
Split into simpler sentences: Bijelo Brdo culture is dated to more than one hundred years later. A theory about "remnant Avar group" in Slovakia in the second half of the 9th century also suffers chronological and geographical problems.