Musannaf Ibn Abi Shayba 2:180

Ubayd Allah narrated to us, from al-Mundhir ibn Tha'labah, who said: I asked Abu Mijlaz [Mukhlad], and I said: "We are in a village where the prayer is performed in congregation. If I pray alone, should I perform the adhan and the iqamah?" He said: "If you wish, the adhan of the public is sufficient for you, and if you wish, then perform the adhan and the iqamah."