Sahih Bukhari Volume 1, Book 12, Hadith Number 739

Narated By Abu Huraira : The Qur’an is recited in every prayer and in those prayers in which Allah’s Apostle recited aloud for us, we recite aloud in the same prayers for you; and the prayers in which the Prophet recited quietly, we recite quietly. If you recite “Al-Fatiha” only it is sufficient but if you recite something else in addition, it is better.