Where is the character of radha is to be found in ithihasa or purana?

There is no character of radha in bhagavata or mahabharata of vyasa. But north indian people worship radha and krishna and poets like jayadeva, narayana theertha and pandaripur saints have sung about radha. In tamilnadu there are only idols of rukmani and satyabhama in sri krishna temples. Hence i want to know about the authentic reference to radha in any ithihasa or purana. I am an ardent devotee of sri rama and have read thoroughly the epics ramayana, bhagavarta and mahabharata in sanskrit and am not a troll.it is my inquisitiveness