Sahih Muslim 380
Sahih Muslim · Book 4: The Book of Prayers · It Is Recommended To Have Two Mu'adhdhin In A Single Masjid
وَحَدَّثَنَا ابْنُ نُمَيْرٍ ، حَدَّثَنَا أَبِي ، حَدَّثَنَا عُبَيْدُ اللَّهِ ، حَدَّثَنَا الْقَاسِمُ ، عَنْ عَائِشَةَ ، مِثْلَهُ .
This hadith has been narrated on the authority of 'A'isha by another chain of transmitters.