The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj) 
Dawud :: Book 10 : Hadith 1986
Narrated Aisha, Ummul Mu'minin:
The Apostle of Allah (peace_be_upon_him) performed two umrahs: one umrah in Dhul-Qa'dah, and the other in Shawwal.
The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)
Dawud :: Book 10 : Hadith 1986
Narrated Aisha, Ummul Mu'minin:
The Apostle of Allah (peace_be_upon_him) performed two umrahs: one umrah in Dhul-Qa'dah, and the other in Shawwal.