http://ayatoilet.com/:

“Iranian” is a geographic term, and also refers to a nationality. “Persians” are an ethnic group inside the country of Iran, in the Iranian Plateau.There are now Persians living in many other countries such as Afghanistan, Tajikistan … in Europe and North American. Immigrants to the U.S. that have come here should correctly be referred to by their ethnicity such as Persian-Americans, in a similar manner as someone can be African-American or European-American.

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