Yahya related to me from Malik from Yahya ibn Said and from Rabiaibn Abi Abd ar Rahman that al-Qasim ibn Muhammad used to recite behindthe imam when the imam did not recite aloud. (ID)
App reference (ID): Book 3, Hadith 43 (ID)
USC-MSA web (English) reference: Book 3, Hadith 43 (ID)
Arabic reference (ID): Book 3, Hadith 190 (ID)