Looking for textual references on the meditative experiences of Buddhists

I am looking for some books/textual references which describe in detail the meditative experiences of advanced practitioners of Buddhism, their experiences with Śūnyatā and the realisation of anatta. It can be the experiences of the Buddha, experiences of the Buddha's senior disciples, experiences of followers who lived during the Buddha's time, or experiences of contemporary Buddhists. Any help would be much appreciated.