Original sentence: Atatürk University, established in 1950, is one of the largest universities in Turkey, having more than forty-thousand students.Little of medieval Erzurum survives beyond scattered individual buildings such as the citadel fortress, and the 13th century Çifte Minareli Medrese (Twin Minaret Madrasa) which was built during the Seljuk period and is regarded as the symbol of the city, appearing also on the coat of arms of the Erzurum Municipality.The city is particularly a popular destination in Turkey for winter sports at the nearby Palandöken Mountain.Tourism also provides a large portion of the province's revenues.Until recent years, the largest source of income and economic activity in the city has been the university
Edited sentence: Little of medieval Erzurum survives beyond scattered individual buildings such as the citadel fortress, and the 13th century Çifte Minareli Medrese (Twin Minaret Madrasa)</ref>.One of the largest source of income and economic activity in the city has been Atatürk University, established in 1950, which is one of the largest universities in Turkey with more than forty-thousand students.The city is a popular destination in Turkey for winter sports at the nearby Palandöken Mountain.Tourism also provides a portion of the province's revenues