Original sentence: According to Richard Nelson Frye, a leading historian of Iranian and Central Asian history, the Persian migration to Central Asia may be considered the beginning of the modern Tajik nation, and ethnic Persians, along with some elements of East-Iranian Bactrians and Sogdians, as the main ancestors of modern Tajiks
Edited sentence: According to Richard Nelson Frye, a leading historian of Iranian and Central Asian history, the the East-Iranian Bactrians and Sogdians may be considered the beginning of the modern Tajik nation, along with some possible elements of Persian migration to Central Asia and ethnic Persians, as the main ancestors of modern Tajiks