Ajahn Mun published nothing. The principal account of him is a biography written by his disciple Ajahn Maha Bua, drawing on what Ajahn Mun had told his students and on what those students remembered, and it is a devotional life rather than a documentary one. It records visions, encounters with deities and with the spirits of departed teachers, knowledge of others' minds, and an account of his final attainment. Readers inside the tradition take these as reportage; historians take them as a portrait of what the tradition values, which is not the same question.
That leaves the ordinary facts thin. He was born in Ubon Ratchathani in 1870, ordained, trained under Ajahn Sao, wandered in Thailand, Laos and Burma for decades, spent long periods in the north around Chiang Mai, returned to the northeast, and died at Sakon Nakhon in 1949 with a large gathering present.
The tradition reached the English-speaking world mainly through Ajahn Chah, who met Ajahn Mun only briefly and belongs to the wider lineage rather than to his immediate circle, and whose Western students founded forest monasteries in Britain, the United States, Australia and New Zealand from the 1970s onward. Those monasteries keep the alms round, the single daily meal and the emphasis on practice over scholarship, in landscapes that contain no forest of the kind Ajahn Mun walked in. This is a living tradition and it is described here rather than instructed.